fix linting

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

.dockerignore

@@ -10,7 +10,9 @@ backend/tmp
 backend/dist
 backend/backend*
 backend/vendor/**
+backend/internal/web/dist/*
+!backend/internal/web/dist/.gitkeep
+
 
-frontend/dist/**
 frontend/node_modules/**
 frontend/pkg/**

.github/workflows/pr.yaml

@@ -42,7 +42,7 @@ jobs:
         uses: actions/upload-artifact@v4
         with:
           name: dist
-          path: backend/internal/web/dist
+          path: frontend/dist
   build_backend:
     name: Build backend
     runs-on: ubuntu-24.04-arm
@@ -97,7 +97,7 @@ jobs:
         uses: actions/download-artifact@v4
         with:
           name: dist
-          path: backend/internal/web/dist
+          path: frontend/dist
       - name: Download backend build
         uses: actions/download-artifact@v4
         with:

_docker/Dockerfile

@@ -39,7 +39,7 @@ COPY --from=base --chown=filebrowser:1000 [ "/app/filebrowser", "./" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/config.yaml", "./data/config.yaml" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/config.yaml", "./" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/reduce-rounded-corners.css", "./" ]
-COPY --from=nbuild --chown=filebrowser:1000 [ "/build/backend/internal/web/dist/", "./internal/web/dist/" ]
+COPY --from=nbuild --chown=filebrowser:1000 [ "/build/frontend/dist/", "./internal/web/dist/" ]
 ## sanity checks
 RUN [ "filebrowser", "version" ]
 RUN [ "ffmpeg", "-version" ]

_docker/Dockerfile.beta

@@ -34,7 +34,7 @@ COPY --from=base --chown=filebrowser:1000 [ "/app/filebrowser", "./" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/config.yaml", "./data/config.yaml" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/config.yaml", "./" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/reduce-rounded-corners.css", "./" ]
-COPY --from=nbuild --chown=filebrowser:1000 [ "/build/backend/internal/web/dist/", "./internal/web/dist/" ]
+COPY --from=nbuild --chown=filebrowser:1000 [ "/build/frontend/dist/", "./internal/web/dist/" ]
 ## sanity checks
 RUN [ "filebrowser", "version" ]
 # exposing default port for auto discovery.

_docker/Dockerfile.media

@@ -68,7 +68,7 @@ COPY --from=base --chown=filebrowser:1000 [ "/app/filebrowser", "./" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/config.yaml", "./data/config.yaml" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/config.yaml", "./" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/reduce-rounded-corners.css", "./" ]
-COPY --from=nbuild --chown=filebrowser:1000 [ "/build/backend/internal/web/dist/", "./internal/web/dist/" ]
+COPY --from=nbuild --chown=filebrowser:1000 [ "/build/frontend/dist/", "./internal/web/dist/" ]
 
 RUN filebrowser version && ffmpeg -version && ffprobe -version
 

_docker/Dockerfile.playwright-general

@@ -12,7 +12,7 @@ WORKDIR /app/backend/
 COPY [ "./backend/filebrowser", "./"]
 COPY [ "./backend/reduce-rounded-corners.css", "./no-rounded.css" ]
 RUN mkdir -p ./internal/web/dist
-COPY [ "./backend/internal/web/dist/", "./internal/web/dist/"]
+COPY [ "./frontend/dist/", "./internal/web/dist/"]
 
 # generate duplicate 1.1MB files
 RUN dd if=/dev/zero of=/app/frontend/tests/playwright-files/1.1MB.bin bs=1024 count=1126 && dd if=/dev/zero of=/app/frontend/tests/playwright-files/1.1mb.bin bs=1024 count=1126

_docker/Dockerfile.playwright-jwt

@@ -6,7 +6,7 @@ COPY [ "./frontend/tests", "./tests" ]
 WORKDIR /app/backend/
 COPY [ "./backend/filebrowser", "./"]
 RUN mkdir -p ./internal/web/dist
-COPY [ "./backend/internal/web/dist/", "./internal/web/dist/"]
+COPY [ "./frontend/dist/", "./internal/web/dist/"]
 RUN apt update && apt install nginx -y
 RUN mv default.conf /etc/nginx/conf.d/default.conf
 RUN sed -i 's/filebrowser/localhost/g' /etc/nginx/conf.d/default.conf

_docker/Dockerfile.playwright-local

@@ -11,7 +11,7 @@ COPY [ "./_docker/src/settings/backend/config.yaml", "./"]
 COPY [ "./_docker/src/settings/backend/database.db.old", "./"]
 COPY [ "./backend/reduce-rounded-corners.css", "./no-rounded.css"]
 RUN mkdir -p ./internal/web/dist
-COPY [ "./backend/internal/web/dist/", "./internal/web/dist/"]
+COPY [ "./frontend/dist/", "./internal/web/dist/"]
 
 ENV FILEBROWSER_PLAYWRIGHT_TEST=true
 RUN ./filebrowser user set testuser1 --password testuser1

_docker/Dockerfile.playwright-no-config

@@ -11,7 +11,7 @@ COPY [ "./frontend/tests/", "./tests" ]
 WORKDIR /app/backend/
 COPY [ "./backend/filebrowser", "./"]
 RUN mkdir -p ./internal/web/dist
-COPY [ "./backend/internal/web/dist/", "./internal/web/dist/"]
+COPY [ "./frontend/dist/", "./internal/web/dist/"]
 
 # Run tests
 ENV FILEBROWSER_PLAYWRIGHT_TEST=true

_docker/Dockerfile.playwright-noauth

@@ -11,7 +11,7 @@ COPY [ "./frontend/tests/playwright-files", "./tests/playwright-files2" ]
 WORKDIR /app/backend/
 COPY [ "./backend/filebrowser", "./"]
 RUN mkdir -p ./internal/web/dist
-COPY [ "./backend/internal/web/dist/", "./internal/web/dist/"]
+COPY [ "./frontend/dist/", "./internal/web/dist/"]
 
 # Run tests
 ENV FILEBROWSER_PLAYWRIGHT_TEST=true

_docker/Dockerfile.playwright-oidc

@@ -7,7 +7,7 @@ WORKDIR /app/backend/
 RUN mkdir -p ./internal/web/dist
 COPY [ "./_docker/src/oidc/backend/", "./"]
 COPY ["./backend/filebrowser", "./"]
-COPY [ "./backend/internal/web/dist/", "./internal/web/dist/"]
+COPY [ "./frontend/dist/", "./internal/web/dist/"]
 
 # Run tests
 WORKDIR /app/frontend

_docker/Dockerfile.playwright-performance

@@ -23,7 +23,7 @@ WORKDIR /app/backend/
 COPY [ "./backend/filebrowser", "./"]
 COPY [ "./backend/reduce-rounded-corners.css", "./no-rounded.css" ]
 RUN mkdir -p ./internal/web/dist
-COPY [ "./backend/internal/web/dist/", "./internal/web/dist/"]
+COPY [ "./frontend/dist/", "./internal/web/dist/"]
 
 ENV FILEBROWSER_PLAYWRIGHT_TEST=true
 ENV CI=true

_docker/Dockerfile.playwright-previews

@@ -13,7 +13,7 @@ COPY [ "./frontend/tests", "./tests" ]
 WORKDIR /app/backend/
 COPY [ "./backend/filebrowser", "./"]
 RUN mkdir -p ./internal/web/dist
-COPY [ "./backend/internal/web/dist/", "./internal/web/dist/"]
+COPY [ "./frontend/dist/", "./internal/web/dist/"]
 
 ENV FILEBROWSER_PLAYWRIGHT_TEST=true
 RUN ./filebrowser & sleep 2 && cd ../frontend && npx playwright test

_docker/Dockerfile.playwright-proxy

@@ -6,7 +6,7 @@ COPY [ "./frontend/tests", "./tests" ]
 WORKDIR /app/backend/
 COPY [ "./backend/filebrowser", "./"]
 RUN mkdir -p ./internal/web/dist
-COPY [ "./backend/internal/web/dist/", "./internal/web/dist/"]
+COPY [ "./frontend/dist/", "./internal/web/dist/"]
 RUN apt update && apt install nginx -y
 RUN mv default.conf /etc/nginx/conf.d/default.conf
 RUN mv .htpasswd /etc/nginx/conf.d/.htpasswd

_docker/Dockerfile.playwright-screenshots

@@ -10,7 +10,7 @@ COPY [ "./backend/filebrowser", "./"]
 COPY [ "./_docker/src/screenshots/backend/*", "./"]
 
 RUN mkdir -p ./internal/web/dist
-COPY [ "./backend/internal/web/dist/", "./internal/web/dist/"]
+COPY [ "./frontend/dist/", "./internal/web/dist/"]
 
 ENV FILEBROWSER_PLAYWRIGHT_TEST=true
 RUN ./filebrowser & sleep 2 && cd ../frontend && npx playwright test --project dark-screenshots

_docker/Dockerfile.playwright-settings

@@ -13,7 +13,7 @@ WORKDIR /app/backend/
 COPY [ "./backend/filebrowser", "./"]
 COPY [ "./backend/reduce-rounded-corners.css", "./no-rounded.css"]
 RUN mkdir -p ./internal/web/dist
-COPY [ "./backend/internal/web/dist/", "./internal/web/dist/"]
+COPY [ "./frontend/dist/", "./internal/web/dist/"]
 
 # Run tests
 ENV FILEBROWSER_PLAYWRIGHT_TEST=true

_docker/Dockerfile.playwright-sharing

@@ -11,7 +11,7 @@ COPY [ "./frontend/tests/", "./tests" ]
 WORKDIR /app/backend/
 COPY [ "./backend/filebrowser", "./"]
 RUN mkdir -p ./internal/web/dist
-COPY [ "./backend/internal/web/dist/", "./internal/web/dist/"]
+COPY [ "./frontend/dist/", "./internal/web/dist/"]
 
 # Run tests
 ENV FILEBROWSER_PLAYWRIGHT_TEST=true

_docker/Dockerfile.purego

@@ -33,7 +33,7 @@ COPY --from=base --chown=filebrowser:1000 [ "/app/filebrowser", "./" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/config.yaml", "./data/config.yaml" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/config.yaml", "./" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/reduce-rounded-corners.css", "./" ]
-COPY --from=nbuild --chown=filebrowser:1000 [ "/build/backend/internal/web/dist/", "./internal/web/dist/" ]
+COPY --from=nbuild --chown=filebrowser:1000 [ "/build/frontend/dist/", "./internal/web/dist/" ]
 ## sanity checks
 RUN [ "filebrowser", "version" ]
 # exposing default port for auto discovery.

_docker/Dockerfile.slim

@@ -32,7 +32,7 @@ COPY --from=base --chown=filebrowser:1000 [ "/app/filebrowser", "./" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/config.yaml", "./data/config.yaml" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/config.yaml", "./" ]
 COPY --from=base --chown=filebrowser:1000 [ "/app/reduce-rounded-corners.css", "./" ]
-COPY --from=nbuild --chown=filebrowser:1000 [ "/build/backend/internal/web/dist/", "./internal/web/dist/" ]
+COPY --from=nbuild --chown=filebrowser:1000 [ "/build/frontend/dist/", "./internal/web/dist/" ]
 ## sanity checks
 RUN [ "filebrowser", "version" ]
 # exposing default port for auto discovery.

backend/go.mod

@@ -21,7 +21,7 @@ require (
 	github.com/gtsteffaniak/go-cache v1.1.0
 	github.com/gtsteffaniak/go-ffmpeg v1.6.2
 	github.com/gtsteffaniak/go-logger v1.1.0
-	github.com/gtsteffaniak/go-media v1.2.0
+	github.com/gtsteffaniak/go-media v1.2.1
 	github.com/kovidgoyal/imaging v1.9.0
 	github.com/pquerna/otp v1.5.0
 	github.com/spf13/afero v1.15.0

backend/go.sum

@@ -167,6 +167,8 @@ github.com/gtsteffaniak/go-logger v1.1.0 h1:baFds+iibuLLNpNLwygz32bDqdsunI6dGWcd
 github.com/gtsteffaniak/go-logger v1.1.0/go.mod h1:rapapTju4D7bwt6h4JOdZNUXDjnp0WkTBd6TN5yWglI=
 github.com/gtsteffaniak/go-media v1.2.0 h1:lbNL/G86uzzH8NaT45DBHKm1r0P7yndIo9pNC7gdqQs=
 github.com/gtsteffaniak/go-media v1.2.0/go.mod h1:EH+5KAVLWfFl0g4W0Xni0qJJH8MUDIhAw4wPcC0mhxY=
+github.com/gtsteffaniak/go-media v1.2.1 h1:SjrPqgQTHnenAFuVh8fTRxk8+qXFEaCxiADx3zkM1OI=
+github.com/gtsteffaniak/go-media v1.2.1/go.mod h1:EH+5KAVLWfFl0g4W0Xni0qJJH8MUDIhAw4wPcC0mhxY=
 github.com/gtsteffaniak/go-vpx v1.0.1 h1:9lSI8yoz6omDChaeV0AJrhdfe2YTrWvJrDENI/bnkAM=
 github.com/gtsteffaniak/go-vpx v1.0.1/go.mod h1:tRCdDZ15oZZTsiwmQAwyH56PTt1jn1C1O0P03oOkoJ8=
 github.com/hashicorp/go-uuid v1.0.3 h1:2gKiV6YVmrJ1i2CKKa9obLvRieoRGviZFL26PcT/Co8=

backend/internal/folio/folio.go

@@ -1,167 +0,0 @@
-// Package folio is the pure-Go document preview fast path using gen2brain/folio.
-// When folio cannot handle a file, callers fall back to the office converter (when configured).
-package folio
-
-import (
-	"bytes"
-	"context"
-	"errors"
-	"fmt"
-	"image"
-	"image/jpeg"
-	"path/filepath"
-	"strings"
-	"sync"
-
-	"github.com/gen2brain/folio/doc"
-	"github.com/gtsteffaniak/filebrowser/backend/pkg/indexing/iteminfo"
-	"github.com/gtsteffaniak/filebrowser/backend/pkg/settings"
-	"github.com/gtsteffaniak/go-logger/logger"
-	"github.com/kovidgoyal/imaging"
-)
-
-var renderMu sync.Mutex
-
-// RenderOptions controls thumbnail sizing for one rendered page.
-type RenderOptions struct {
-	MaxWidth    int
-	MaxHeight   int
-	Fill        bool
-	JpegQuality int
-	Original    bool
-}
-
-// Enabled reports whether the folio fast path may run.
-func Enabled() bool {
-	return !settings.AlwaysUseOnlyOfficeEnabled()
-}
-
-// SupportsExtension reports whether folio targets the file extension (including leading dot).
-func SupportsExtension(ext string) bool {
-	ext = strings.ToLower(ext)
-	if !strings.HasPrefix(ext, ".") {
-		ext = "." + ext
-	}
-	return iteminfo.FolioConvertable[ext]
-}
-
-func logFallback(op, path string, err error) {
-	if errors.Is(err, doc.ErrUnsupported) {
-		logger.Warningf("folio does not support %s for %s (%v); using office converter if configured", op, path, err)
-		return
-	}
-	logger.Errorf("folio %s failed for %s: %v; falling back to office converter if configured", op, path, err)
-}
-
-// RenderPageJPEG renders one document page to JPEG. ok is true when folio returned bytes.
-// name and mimetype should match the file being previewed; they control eligibility for
-// folio (content sniffing does not depend on the path extension).
-func RenderPageJPEG(ctx context.Context, path string, pageNumber int, opts RenderOptions, name, mimetype string) (data []byte, ok bool, err error) {
-	if !Enabled() {
-		return nil, false, nil
-	}
-	if name == "" {
-		name = filepath.Base(path)
-	}
-	if !SupportsPreview(name, mimetype) {
-		return nil, false, nil
-	}
-	if ctx.Err() != nil {
-		return nil, false, ctx.Err()
-	}
-
-	type result struct {
-		data []byte
-		err  error
-	}
-	done := make(chan result, 1)
-	go func() {
-		defer func() {
-			if r := recover(); r != nil {
-				done <- result{err: fmt.Errorf("folio render panicked: %v", r)}
-			}
-		}()
-		data, err := renderPageJPEG(ctx, path, name, mimetype, pageNumber, opts)
-		done <- result{data: data, err: err}
-	}()
-
-	select {
-	case <-ctx.Done():
-		return nil, false, ctx.Err()
-	case res := <-done:
-		if res.err != nil {
-			if !errors.Is(res.err, context.Canceled) && !errors.Is(res.err, context.DeadlineExceeded) {
-				logFallback("render", path, res.err)
-			}
-			return nil, false, res.err
-		}
-		if len(res.data) == 0 {
-			return nil, false, fmt.Errorf("folio render returned empty jpeg")
-		}
-		return res.data, true, nil
-	}
-}
-
-func renderPageJPEG(ctx context.Context, path, name, mimetype string, pageNumber int, opts RenderOptions) ([]byte, error) {
-	renderMu.Lock()
-	defer renderMu.Unlock()
-	if err := ctx.Err(); err != nil {
-		return nil, err
-	}
-
-	d, err := openDocument(path, name, mimetype)
-	if err != nil {
-		return nil, err
-	}
-	defer d.Close()
-
-	if pageNumber < 0 || pageNumber >= d.NumPages() {
-		return nil, fmt.Errorf("invalid page number %d (pages: %d)", pageNumber, d.NumPages())
-	}
-
-	p, err := d.Page(pageNumber)
-	if err != nil {
-		return nil, err
-	}
-
-	var img image.Image
-	if opts.Original || opts.MaxWidth <= 0 || opts.MaxHeight <= 0 {
-		const maxEdge = 4096
-		rgba, err := p.ImageDPI(150)
-		if err != nil {
-			return nil, err
-		}
-		img = rgba
-		w, h := rgba.Bounds().Dx(), rgba.Bounds().Dy()
-		if w > maxEdge || h > maxEdge {
-			scale := min(float64(maxEdge)/float64(w), float64(maxEdge)/float64(h))
-			newW := max(1, int(float64(w)*scale))
-			newH := max(1, int(float64(h)*scale))
-			img = imaging.Resize(img, newW, newH, imaging.Lanczos)
-		}
-	} else {
-		rgba, err := p.ImageDPI(150)
-		if err != nil {
-			return nil, err
-		}
-		img = rgba
-		if opts.Fill {
-			img = imaging.Fill(img, opts.MaxWidth, opts.MaxHeight, imaging.Center, imaging.Lanczos)
-		} else {
-			b := img.Bounds()
-			if b.Dx() > opts.MaxWidth || b.Dy() > opts.MaxHeight {
-				img = imaging.Fit(img, opts.MaxWidth, opts.MaxHeight, imaging.Lanczos)
-			}
-		}
-	}
-
-	q := opts.JpegQuality
-	if q <= 0 {
-		q = 85
-	}
-	var buf bytes.Buffer
-	if err := jpeg.Encode(&buf, img, &jpeg.Options{Quality: q}); err != nil {
-		return nil, err
-	}
-	return buf.Bytes(), nil
-}

backend/internal/preview/doc.go

@@ -5,16 +5,26 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/gtsteffaniak/filebrowser/backend/internal/folio"
 	"github.com/gtsteffaniak/filebrowser/backend/pkg/indexing/iteminfo"
 )
 
+const (
+	// docPreviewTimeout bounds small, large and xlarge page renders.
+	docPreviewTimeout = 2 * time.Second
+	// docOriginalTimeout bounds "original" renders, which are higher resolution.
+	docOriginalTimeout = 10 * time.Second
+)
+
 func (s *Service) GenerateImageFromDoc(ctx context.Context, file iteminfo.ExtendedFileInfo, pageNumber int, previewSize string) ([]byte, error) {
 	if ctx.Err() != nil {
 		return nil, ctx.Err()
 	}
 
-	timeoutCtx, cancel := context.WithTimeout(ctx, 2*time.Second)
+	timeout := docPreviewTimeout
+	if previewSize == "original" {
+		timeout = docOriginalTimeout
+	}
+	timeoutCtx, cancel := context.WithTimeout(ctx, timeout)
 	defer cancel()
 
 	opts, err := folioRenderOptions(previewSize)
@@ -22,7 +32,7 @@ func (s *Service) GenerateImageFromDoc(ctx context.Context, file iteminfo.Extend
 		return nil, err
 	}
 
-	imageBytes, ok, err := folio.RenderPageJPEG(timeoutCtx, file.RealPath, pageNumber, opts, file.Name, file.Type)
+	imageBytes, ok, err := renderDocPageJPEG(timeoutCtx, file.RealPath, pageNumber, opts, file.Name, file.Type)
 	if !ok {
 		if err != nil {
 			return nil, err
@@ -30,20 +40,22 @@ func (s *Service) GenerateImageFromDoc(ctx context.Context, file iteminfo.Extend
 		return nil, nil
 	}
 	if timeoutCtx.Err() != nil {
-		return nil, fmt.Errorf("document preview generation timed out after 2 seconds for '%s'", file.Name)
+		return nil, fmt.Errorf("document preview generation timed out after %s for '%s'", timeout, file.Name)
 	}
 	return imageBytes, nil
 }
 
-func folioRenderOptions(previewSize string) (folio.RenderOptions, error) {
+// folioRenderOptions maps a preview size onto the same dimensions, fill mode and JPEG quality
+// the image pipeline uses (see getPreviewOptions); "original" renders at full resolution.
+func folioRenderOptions(previewSize string) (docRenderOptions, error) {
 	if previewSize == "original" {
-		return folio.RenderOptions{Original: true, JpegQuality: QualityHigh.jpegQuality()}, nil
+		return docRenderOptions{Original: true, JpegQuality: QualityHigh.jpegQuality()}, nil
 	}
 	opts, err := getPreviewOptions(previewSize)
 	if err != nil {
-		return folio.RenderOptions{}, err
+		return docRenderOptions{}, err
 	}
-	return folio.RenderOptions{
+	return docRenderOptions{
 		MaxWidth:    opts.Width,
 		MaxHeight:   opts.Height,
 		Fill:        opts.ResizeMode == ResizeModeFill,

backend/internal/preview/doc_text_integration_test.go

@@ -5,7 +5,6 @@ import (
 	"path/filepath"
 	"testing"
 
-	"github.com/gtsteffaniak/filebrowser/backend/internal/folio"
 	"github.com/gtsteffaniak/filebrowser/backend/pkg/indexing/iteminfo"
 	"github.com/stretchr/testify/require"
 )
@@ -17,7 +16,7 @@ func TestFolioRender_utf8TruncatedPlaywrightFile(t *testing.T) {
 	}
 	opts, err := folioRenderOptions("small")
 	require.NoError(t, err)
-	data, ok, err := folio.RenderPageJPEG(t.Context(), realPath, 0, opts, "utf8-truncated.txt", "text/plain")
+	data, ok, err := renderDocPageJPEG(t.Context(), realPath, 0, opts, "utf8-truncated.txt", "text/plain")
 	require.NoError(t, err)
 	require.True(t, ok, "err=%v", err)
 	require.NotEmpty(t, data)
@@ -29,7 +28,7 @@ func TestFolioRender_cssAsTxt(t *testing.T) {
 	require.NoError(t, os.WriteFile(cssPath, []byte("body { color: red; }\n"), 0o644))
 	opts, err := folioRenderOptions("small")
 	require.NoError(t, err)
-	data, ok, err := folio.RenderPageJPEG(t.Context(), cssPath, 0, opts, "styles.css", "text/css")
+	data, ok, err := renderDocPageJPEG(t.Context(), cssPath, 0, opts, "styles.css", "text/css")
 	require.NoError(t, err)
 	require.True(t, ok, "err=%v", err)
 	require.NotEmpty(t, data)

backend/internal/preview/folio.go

@@ -0,0 +1,208 @@
+// folio.go is the pure-Go document preview fast path using gen2brain/folio.
+// When folio cannot handle a file, callers fall back to the office converter (when configured).
+package preview
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"image"
+	"image/jpeg"
+	"path/filepath"
+	"sync"
+
+	"github.com/gen2brain/folio/doc"
+	"github.com/gtsteffaniak/filebrowser/backend/pkg/settings"
+	"github.com/gtsteffaniak/go-logger/logger"
+	"github.com/kovidgoyal/imaging"
+)
+
+const (
+	// docSupersample renders a page at this multiple of the target box before the
+	// final downscale. Rasterized text needs the extra pixels to stay crisp.
+	docSupersample = 2
+	// docOriginalDPI is the resolution used for "original" page previews.
+	docOriginalDPI = 200
+	// docMaxRenderEdge caps the longest edge of a rendered page, in pixels.
+	docMaxRenderEdge = 4096
+	// docMinDPI and docMaxDPI bound the computed render resolution.
+	docMinDPI = 36.0
+	docMaxDPI = 600.0
+)
+
+var renderMu sync.Mutex
+
+// docRenderOptions controls the size and quality of one rendered document page.
+type docRenderOptions struct {
+	MaxWidth    int
+	MaxHeight   int
+	Fill        bool
+	JpegQuality int
+	Original    bool
+}
+
+// folioEnabled reports whether the folio fast path may run.
+func folioEnabled() bool {
+	return !settings.AlwaysUseOnlyOfficeEnabled()
+}
+
+func logFolioFallback(op, path string, err error) {
+	if errors.Is(err, doc.ErrUnsupported) {
+		logger.Warningf("folio does not support %s for %s (%v); using office converter if configured", op, path, err)
+		return
+	}
+	logger.Errorf("folio %s failed for %s: %v; falling back to office converter if configured", op, path, err)
+}
+
+// renderDocPageJPEG renders one document page to JPEG. ok is true when folio returned bytes.
+// name and mimetype should match the file being previewed; they control eligibility for
+// folio (content sniffing does not depend on the path extension).
+func renderDocPageJPEG(ctx context.Context, path string, pageNumber int, opts docRenderOptions, name, mimetype string) (data []byte, ok bool, err error) {
+	if !folioEnabled() {
+		return nil, false, nil
+	}
+	if name == "" {
+		name = filepath.Base(path)
+	}
+	if !folioSupportsPreview(name, mimetype) {
+		return nil, false, nil
+	}
+	if ctx.Err() != nil {
+		return nil, false, ctx.Err()
+	}
+
+	type result struct {
+		data []byte
+		err  error
+	}
+	done := make(chan result, 1)
+	go func() {
+		defer func() {
+			if r := recover(); r != nil {
+				done <- result{err: fmt.Errorf("folio render panicked: %v", r)}
+			}
+		}()
+		data, err := renderPageJPEG(ctx, path, name, mimetype, pageNumber, opts)
+		done <- result{data: data, err: err}
+	}()
+
+	select {
+	case <-ctx.Done():
+		return nil, false, ctx.Err()
+	case res := <-done:
+		if res.err != nil {
+			if !errors.Is(res.err, context.Canceled) && !errors.Is(res.err, context.DeadlineExceeded) {
+				logFolioFallback("render", path, res.err)
+			}
+			return nil, false, res.err
+		}
+		if len(res.data) == 0 {
+			return nil, false, fmt.Errorf("folio render returned empty jpeg")
+		}
+		return res.data, true, nil
+	}
+}
+
+func renderPageJPEG(ctx context.Context, path, name, mimetype string, pageNumber int, opts docRenderOptions) ([]byte, error) {
+	renderMu.Lock()
+	defer renderMu.Unlock()
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+
+	d, err := openDocument(path, name, mimetype)
+	if err != nil {
+		return nil, err
+	}
+	defer d.Close()
+
+	if pageNumber < 0 || pageNumber >= d.NumPages() {
+		return nil, fmt.Errorf("invalid page number %d (pages: %d)", pageNumber, d.NumPages())
+	}
+
+	p, err := d.Page(pageNumber)
+	if err != nil {
+		return nil, err
+	}
+
+	boxed := !opts.Original && opts.MaxWidth > 0 && opts.MaxHeight > 0
+	var dpi float64
+	if boxed {
+		dpi = docBoxRenderDPI(p, d.Kind(), opts.MaxWidth, opts.MaxHeight, opts.Fill)
+	} else {
+		dpi = docOriginalRenderDPI(p, d.Kind())
+	}
+
+	rendered, err := p.ImageDPI(dpi)
+	if err != nil {
+		return nil, err
+	}
+	if rendered == nil {
+		return nil, fmt.Errorf("folio rendered no image for page %d", pageNumber)
+	}
+
+	var img image.Image = rendered
+	if boxed {
+		// The page was rendered at docSupersample times the target, so this
+		// single high-quality downscale produces the anti-aliased final image.
+		if opts.Fill {
+			img = imaging.Fill(img, opts.MaxWidth, opts.MaxHeight, imaging.Center, imaging.Lanczos)
+		} else {
+			img = imaging.Fit(img, opts.MaxWidth, opts.MaxHeight, imaging.Lanczos)
+		}
+	}
+
+	q := opts.JpegQuality
+	if q <= 0 {
+		q = 85
+	}
+	var buf bytes.Buffer
+	if err := jpeg.Encode(&buf, img, &jpeg.Options{Quality: q}); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// docUnitDPI is the resolution at which folio's ImageDPI renders page units one to one:
+// 72 for PDF and book pages, 96 for drawings (SVG).
+func docUnitDPI(kind doc.Kind) float64 {
+	if kind == doc.KindSVG {
+		return 96
+	}
+	return 72
+}
+
+// docMaxEdgeDPI is the highest resolution at which the longest page edge stays within docMaxRenderEdge.
+func docMaxEdgeDPI(p doc.Page, kind doc.Kind) float64 {
+	b := p.Bounds()
+	longest := float64(max(b.X1-b.X0, b.Y1-b.Y0))
+	if longest <= 0 {
+		return docMinDPI
+	}
+	return docUnitDPI(kind) * docMaxRenderEdge / longest
+}
+
+// docBoxRenderDPI picks the resolution for a page that will be scaled into a boxW x boxH target.
+// Fill covers the box; fit stays inside it. The page is rendered at docSupersample times the target.
+func docBoxRenderDPI(p doc.Page, kind doc.Kind, boxW, boxH int, fill bool) float64 {
+	b := p.Bounds()
+	pw, ph := float64(b.X1-b.X0), float64(b.Y1-b.Y0)
+	if pw <= 0 || ph <= 0 {
+		return docMinDPI
+	}
+	// Scale (pixels per page unit) needed for the supersampled render to reach the box on each axis.
+	sx := float64(boxW*docSupersample) / pw
+	sy := float64(boxH*docSupersample) / ph
+	s := min(sx, sy)
+	if fill {
+		s = max(sx, sy)
+	}
+	dpi := min(s*docUnitDPI(kind), docMaxEdgeDPI(p, kind))
+	return min(max(dpi, docMinDPI), docMaxDPI)
+}
+
+// docOriginalRenderDPI picks the resolution for "original" previews: docOriginalDPI, capped by docMaxRenderEdge.
+func docOriginalRenderDPI(p doc.Page, kind doc.Kind) float64 {
+	return min(docOriginalDPI, docMaxEdgeDPI(p, kind))
+}

backend/internal/preview/folio_open.go

@@ -1,4 +1,4 @@
-package folio
+package preview
 
 import (
 	"fmt"
@@ -17,9 +17,9 @@ const folioTextCheckWindow = 4096 // html.readsAsText validation window
 // maxTextPreviewLoad is the most plain-text we read for a first-page thumbnail.
 const maxTextPreviewLoad = 32 << 10 // 32 KiB
 
-// SupportsPreview reports whether folio should attempt this file (name + MIME).
+// folioSupportsPreview reports whether folio should attempt this file (name + MIME).
 // doc.Open sniffs content; extensions like .css are not in FolioConvertable but still render.
-func SupportsPreview(name, mimetype string) bool {
+func folioSupportsPreview(name, mimetype string) bool {
 	ext := strings.ToLower(filepath.Ext(name))
 	if iteminfo.FolioConvertable[ext] {
 		return true

backend/internal/preview/folio_test.go

@@ -1,4 +1,4 @@
-package folio
+package preview
 
 import (
 	"os"
@@ -8,12 +8,12 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestRenderPageJPEG_txt(t *testing.T) {
+func TestRenderDocPageJPEG_txt(t *testing.T) {
 	dir := t.TempDir()
 	path := filepath.Join(dir, "hello.txt")
 	require.NoError(t, os.WriteFile(path, []byte("Hello folio preview"), 0o644))
 
-	data, ok, err := RenderPageJPEG(t.Context(), path, 0, RenderOptions{
+	data, ok, err := renderDocPageJPEG(t.Context(), path, 0, docRenderOptions{
 		MaxWidth:    256,
 		MaxHeight:   256,
 		Fill:        true,
@@ -26,8 +26,8 @@ func TestRenderPageJPEG_txt(t *testing.T) {
 	require.Equal(t, byte(0xd8), data[1])
 }
 
-func TestRenderPageJPEG_unsupportedExtension(t *testing.T) {
-	data, ok, err := RenderPageJPEG(t.Context(), "/nonexistent/file.xyz", 0, RenderOptions{}, "file.xyz", "application/octet-stream")
+func TestRenderDocPageJPEG_unsupportedExtension(t *testing.T) {
+	data, ok, err := renderDocPageJPEG(t.Context(), "/nonexistent/file.xyz", 0, docRenderOptions{}, "file.xyz", "application/octet-stream")
 	require.NoError(t, err)
 	require.False(t, ok)
 	require.Nil(t, data)

backend/internal/preview/folio_utf8_test.go

@@ -1,4 +1,4 @@
-package folio
+package preview
 
 import (
 	"os"
@@ -37,22 +37,17 @@ func TestSanitizeFolioText_stripsNUL(t *testing.T) {
 	raw := []byte("hello\x00world")
 	got := sanitizeFolioText(raw)
 	require.Equal(t, []byte("hello world"), got)
-	opts, err := folioRenderOptionsForTest()
-	require.NoError(t, err)
 
+	opts := docRenderOptions{MaxWidth: 256, MaxHeight: 256, Fill: true, JpegQuality: 80}
 	dir := t.TempDir()
 	path := filepath.Join(dir, "nul.txt")
 	require.NoError(t, os.WriteFile(path, raw, 0o600))
-	data, ok, err := RenderPageJPEG(t.Context(), path, 0, opts, "nul.txt", "text/plain")
+	data, ok, err := renderDocPageJPEG(t.Context(), path, 0, opts, "nul.txt", "text/plain")
 	require.NoError(t, err)
 	require.True(t, ok, "err=%v", err)
 	require.NotEmpty(t, data)
 }
 
-func folioRenderOptionsForTest() (RenderOptions, error) {
-	return RenderOptions{MaxWidth: 256, MaxHeight: 256, Fill: true, JpegQuality: 80}, nil
-}
-
 func TestReadTextPreviewPrefix_cap(t *testing.T) {
 	dir := t.TempDir()
 	path := filepath.Join(dir, "big.log")

backend/internal/preview/preview.go

@@ -18,7 +18,6 @@ import (
 	"github.com/gtsteffaniak/filebrowser/backend/internal/adapters/fs/fileutils"
 	"github.com/gtsteffaniak/filebrowser/backend/internal/embeddedpreview"
 	"github.com/gtsteffaniak/filebrowser/backend/internal/ffmpeg"
-	"github.com/gtsteffaniak/filebrowser/backend/internal/folio"
 	"github.com/gtsteffaniak/filebrowser/backend/internal/imagemeta"
 	"github.com/gtsteffaniak/filebrowser/backend/pkg/indexing/iteminfo"
 	"github.com/gtsteffaniak/filebrowser/backend/pkg/settings"
@@ -481,7 +480,7 @@ func GeneratePreviewWithMD5(ctx context.Context, file iteminfo.ExtendedFileInfo,
 
 	// Folio document previews render at target size in-process; they skip imageSem.
 	previewTypeEarly := determinePreviewType(file)
-	skipImageSem := previewTypeEarly == previewTypeDocument && folio.Enabled() && iteminfo.HasDocConvertableExtension(file.Name, file.Type)
+	skipImageSem := previewTypeEarly == previewTypeDocument && folioEnabled() && iteminfo.HasDocConvertableExtension(file.Name, file.Type)
 	// True when the semaphore block below holds a permit for this whole function.
 	imagePermitHeld := !skipImageSem
 	if !skipImageSem {
@@ -576,7 +575,7 @@ func GeneratePreviewWithMD5(ctx context.Context, file iteminfo.ExtendedFileInfo,
 	// Video thumbnails come from go-media or ffmpeg already sized to the preview
 	// box, so they are final and need no ffmpeg gate here.
 	if !fromEmbeddedPreview && (previewType == previewTypeImage ||
-		(previewType == previewTypeDocument && folio.Enabled() && iteminfo.HasDocConvertableExtension(file.Name, file.Type)) ||
+		(previewType == previewTypeDocument && folioEnabled() && iteminfo.HasDocConvertableExtension(file.Name, file.Type)) ||
 		previewType == previewTypeVideo) {
 		if err := service.fileCache.Store(ctx, cacheKey, imageBytes); err != nil {
 			logger.Errorf("failed to cache image: %v", err)

backend/internal/web/server.go

@@ -42,7 +42,7 @@ func initRuntime(deps Deps, assets fs.FS) {
 	initSettingsSecretMarkers()
 }
 
-// Embed the frontend build output under internal/web/dist (see frontend `npm run build`).
+// Embed the frontend build output under internal/web/dist (see `make embed-frontend` after `npm run build` in frontend/).
 //
 //go:embed dist/*
 var assets embed.FS

backend/internal/web/static.go

@@ -245,6 +245,7 @@ func handleWithStaticData(w http.ResponseWriter, r *http.Request, d *requestCont
 		manifestURL = staticURL + "/site.webmanifest?" + query.Encode()
 	}
 
+	// only include constant values that don't change during a users session
 	data["htmlVars"] = map[string]interface{}{
 		"title":              title,
 		"customCSS":          template.CSS(settings.Config.Frontend.Styling.CustomCSSRaw),
@@ -272,6 +273,7 @@ func handleWithStaticData(w http.ResponseWriter, r *http.Request, d *requestCont
 		"devMode":            settings.Env.IsDevMode,
 	}
 
+	// only include constant values that don't change during a users session
 	data["globalVars"] = map[string]interface{}{
 		"name":                          settings.Config.Frontend.Name,
 		"minSearchLength":               settings.Config.Server.MinSearchLength,
@@ -302,7 +304,6 @@ func handleWithStaticData(w http.ResponseWriter, r *http.Request, d *requestCont
 		"transcodeProfiles":             settings.EnabledTranscodeProfiles(),
 		"transcodeMaxPerUser":           settings.TranscodeMaxConcurrentPerUser(),
 		"docPreviewExtensions":          iteminfo.DocPreviewExtensionsForSPA(),
-		"textPreviewExtensions":         iteminfo.TextPreviewExtensionsForSPA(),
 		"updateAvailable":               utils.GetUpdateAvailableUrl(),
 		"disableNavButtons":             disableNavButtons,
 		"userSelectableThemes":          settings.Config.Frontend.Styling.CustomThemeOptions,
@@ -324,6 +325,7 @@ func handleWithStaticData(w http.ResponseWriter, r *http.Request, d *requestCont
 		"playwrightTest":                settings.Env.IsPlaywright,
 		"officeProduct":                 officeProductForSPA(),
 		"officeExtensions":              wopiExtensionsForSPA(),
+		"textPreviewMimeTypes":          iteminfo.TextPreviewMimeTypes(),
 	}
 
 	cspNonce, err := utils.CSPNonce()

backend/internal/web/textpreview.go

@@ -5,8 +5,6 @@ import (
 	"fmt"
 	"net/http"
 	"os"
-	"path/filepath"
-	"strings"
 
 	"github.com/gtsteffaniak/filebrowser/backend/internal/adapters/fs/files"
 	"github.com/gtsteffaniak/filebrowser/backend/internal/preview"
@@ -101,10 +99,10 @@ func serveTextPreview(w http.ResponseWriter, r *http.Request, info *iteminfo.Ext
 	if info.Type == "directory" {
 		return http.StatusUnsupportedMediaType, fmt.Errorf("directories have no text preview")
 	}
-	kind := iteminfo.TextPreviewKind(strings.ToLower(filepath.Ext(info.Name)))
-	if kind == "" {
+	if !iteminfo.IsTextPreviewable(info.Type) {
 		return http.StatusUnsupportedMediaType, fmt.Errorf("unsupported file type for text preview")
 	}
+	kind := iteminfo.TextPreviewRenderKind(info.Name)
 	// Bound concurrent reads and RTF conversions with the preview service's shared
 	// image-processor semaphore, so a listing of many text files cannot open an
 	// unbounded number of file handles at once.

backend/pkg/indexing/indexingFiles.go

@@ -1597,7 +1597,7 @@ func setFilePreviewFlags(fileInfo *iteminfo.ItemInfo, realPath string) {
 	}
 	// Text-like files are rendered by the text preview endpoint (not the image pipeline),
 	// so this runs before Folio/OnlyOffice. SVG is not a text preview type and stays an image.
-	if iteminfo.IsTextPreviewable(fileInfo.Name) {
+	if iteminfo.IsTextPreviewable(fileInfo.Type) {
 		fileInfo.HasPreview = true
 		return
 	}

backend/pkg/indexing/iteminfo/conditions.go

@@ -271,57 +271,57 @@ var compressedFile = map[string]bool{
 
 // Raw camera image: extension -> MIME type (single source for IsRawImage + type detection)
 var rawImageMimeType = map[string]string{
-	".cr2":  "image/x-canon-cr2",
-	".cr3":  "image/x-canon-cr3",
-	".nef":  "image/x-nikon-nef",
-	".nrw":  "image/x-nikon-nef",
-	".arw":  "image/x-sony-arw",
-	".srf":  "image/x-sony-arw",
-	".sr2":  "image/x-sony-arw",
-	".orf":  "image/x-olympus-orf",
-	".rw2":  "image/x-panasonic-rw2",
-	".raw":  "image/x-panasonic-raw",
-	".dng":  "image/x-adobe-dng",
-	".raf":  "image/x-fuji-raf",
-	".pef":  "image/x-pentax-pef",
-	".ptx":  "image/x-pentax-pef",
-	".rwl":  "image/x-leica-rwl",
-	".3fr":  "image/x-hasselblad-3fr",
-	".fff":  "image/x-hasselblad-fff",
-	".erf":  "image/x-epson-erf",
-	".mrw":  "image/x-minolta-mrw",
-	".dcr":  "image/x-kodak-dcr",
-	".kdc":  "image/x-kodak-dcr",
-	".dc2":  "image/x-kodak-dc2",
-	".x3f":  "image/x-sigma-x3f",
-	".iiq":  "image/x-phaseone-iiq",
-	".nkc":  "image/x-kodak-nkc",
-	".r3d":  "image/x-red-r3d",
+	".cr2": "image/x-canon-cr2",
+	".cr3": "image/x-canon-cr3",
+	".nef": "image/x-nikon-nef",
+	".nrw": "image/x-nikon-nef",
+	".arw": "image/x-sony-arw",
+	".srf": "image/x-sony-arw",
+	".sr2": "image/x-sony-arw",
+	".orf": "image/x-olympus-orf",
+	".rw2": "image/x-panasonic-rw2",
+	".raw": "image/x-panasonic-raw",
+	".dng": "image/x-adobe-dng",
+	".raf": "image/x-fuji-raf",
+	".pef": "image/x-pentax-pef",
+	".ptx": "image/x-pentax-pef",
+	".rwl": "image/x-leica-rwl",
+	".3fr": "image/x-hasselblad-3fr",
+	".fff": "image/x-hasselblad-fff",
+	".erf": "image/x-epson-erf",
+	".mrw": "image/x-minolta-mrw",
+	".dcr": "image/x-kodak-dcr",
+	".kdc": "image/x-kodak-dcr",
+	".dc2": "image/x-kodak-dc2",
+	".x3f": "image/x-sigma-x3f",
+	".iiq": "image/x-phaseone-iiq",
+	".nkc": "image/x-kodak-nkc",
+	".r3d": "image/x-red-r3d",
 }
 
 // 3D model extension -> MIME type (single source for Is3DModel + type detection)
 var model3DMimeType = map[string]string{
-	".gltf":  "model/gltf+json",
-	".glb":   "model/gltf-binary",
-	".obj":   "model/obj",
-	".fbx":   "model/fbx",
-	".stl":   "model/stl",
-	".ply":   "model/ply",
-	".dae":   "model/vnd.collada+xml",
-	".3mf":   "model/3mf",
-	".3ds":   "model/3ds",
-	".usdz":  "model/vnd.usdz+zip",
-	".usd":   "model/vnd.usd+zip",
-	".usda":  "model/vnd.usd+zip",
-	".usdc":  "model/vnd.usd+zip",
-	".amf":   "model/x-amf",
-	".vrml":  "model/vrml",
-	".wrl":   "model/vrml",
-	".vtk":   "model/vtk",
-	".vtp":   "model/vtk",
-	".pcd":   "model/pcd",
-	".xyz":   "model/xyz",
-	".vox":   "model/vox",
+	".gltf": "model/gltf+json",
+	".glb":  "model/gltf-binary",
+	".obj":  "model/obj",
+	".fbx":  "model/fbx",
+	".stl":  "model/stl",
+	".ply":  "model/ply",
+	".dae":  "model/vnd.collada+xml",
+	".3mf":  "model/3mf",
+	".3ds":  "model/3ds",
+	".usdz": "model/vnd.usdz+zip",
+	".usd":  "model/vnd.usd+zip",
+	".usda": "model/vnd.usd+zip",
+	".usdc": "model/vnd.usd+zip",
+	".amf":  "model/x-amf",
+	".vrml": "model/vrml",
+	".wrl":  "model/vrml",
+	".vtk":  "model/vtk",
+	".vtp":  "model/vtk",
+	".pcd":  "model/pcd",
+	".xyz":  "model/xyz",
+	".vox":  "model/vox",
 }
 
 var audioMetadataTypes = map[string]bool{
@@ -560,20 +560,47 @@ func TextPreviewKind(ext string) string {
 	return textPreviewKinds[ext]
 }
 
-// IsTextPreviewable reports whether a file name uses the text preview endpoint.
-func IsTextPreviewable(name string) bool {
-	return textPreviewKinds[strings.ToLower(filepath.Ext(name))] != ""
+// textPreviewMimeTypes are non-text/* mimetypes that textTypes extensions resolve to
+// (see the custom table in backend/internal/adapters/fs/files/mime.go). The frontend
+// receives this list through globalVars (backend/internal/web/static.go), so it is
+// the single source of truth.
+// Do not add mimetypes shared with binaries (e.g. application/x-msdownload for .exe).
+var textPreviewMimeTypes = map[string]bool{
+	"application/json":         true,
+	"application/yaml":         true,
+	"application/x-yaml":       true,
+	"application/sql":          true,
+	"application/x-sql":        true,
+	"application/x-sh":         true,
+	"application/x-php":        true,
+	"application/x-powershell": true,
+	"application/x-tex":        true,
+	"application/toml":         true,
+	"application/x-ruby":       true,
 }
 
-// TextPreviewExtensionsForSPA groups text preview extensions (without dots) by renderer kind.
-// The frontend uses this to decide which items get a text preview container.
-func TextPreviewExtensionsForSPA() map[string][]string {
-	out := make(map[string][]string)
-	for ext, kind := range textPreviewKinds {
-		out[kind] = append(out[kind], strings.TrimPrefix(ext, "."))
-	}
-	for kind := range out {
-		sort.Strings(out[kind])
-	}
-	return out
+// IsTextPreviewable reports whether an item uses the text preview endpoint. The decision
+// is the item's mimetype: every text/* type and the textPreviewMimeTypes allowlist.
+func IsTextPreviewable(mimetype string) bool {
+	return strings.HasPrefix(mimetype, "text/") || textPreviewMimeTypes[mimetype]
+}
+
+// TextPreviewMimeTypes returns the non-text/* allowlist in sorted order, for the
+// frontend's globalVars. Sorting keeps the served value stable across restarts.
+func TextPreviewMimeTypes() []string {
+	types := make([]string, 0, len(textPreviewMimeTypes))
+	for mt := range textPreviewMimeTypes {
+		types = append(types, mt)
+	}
+	sort.Strings(types)
+	return types
+}
+
+// TextPreviewRenderKind returns the renderer kind for a text-previewable file: the
+// extension-specific kind when one exists, otherwise "plain".
+func TextPreviewRenderKind(name string) string {
+	if kind := TextPreviewKind(strings.ToLower(filepath.Ext(name))); kind != "" {
+		return kind
+	}
+	return "plain"
 }

backend/pkg/indexing/iteminfo/text_preview_test.go

@@ -1,7 +1,7 @@
 package iteminfo
 
 import (
-	"slices"
+	"sort"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -22,21 +22,30 @@ func TestTextPreviewKinds(t *testing.T) {
 }
 
 func TestIsTextPreviewable(t *testing.T) {
-	require.True(t, IsTextPreviewable("Notes.TXT"))
-	require.True(t, IsTextPreviewable("dir/readme.md"))
-	require.False(t, IsTextPreviewable("image.svg"))
-	require.False(t, IsTextPreviewable("noext"))
-}
-
-func TestTextPreviewExtensionsForSPA(t *testing.T) {
-	groups := TextPreviewExtensionsForSPA()
-	require.Contains(t, groups["markdown"], "md")
-	require.Contains(t, groups["rtf"], "rtf")
-	require.True(t, slices.Contains(groups["code"], "go"))
-	require.False(t, slices.Contains(groups["code"], "svg"))
-	for _, exts := range groups {
-		for _, ext := range exts {
-			require.NotContains(t, ext, ".", "extensions must not have a leading dot")
-		}
+	for _, mt := range []string{"text/plain", "text/markdown", "text/lyrics", "text/x-go", "text/html"} {
+		require.True(t, IsTextPreviewable(mt), mt)
+	}
+	for _, mt := range []string{"application/json", "application/yaml", "application/sql", "application/x-sh", "application/x-php", "application/x-powershell", "application/x-tex"} {
+		require.True(t, IsTextPreviewable(mt), mt)
+	}
+	// Mimetypes shared with binaries (.exe, .bat via application/x-msdownload) must stay non-previewable.
+	for _, mt := range []string{"", "image/svg+xml", "application/pdf", "application/x-sqlite3", "application/postscript", "application/backup", "application/wasm", "application/x-msdownload", "application/x-msdos-program", "application/octet-stream"} {
+		require.False(t, IsTextPreviewable(mt), mt)
 	}
 }
+
+func TestTextPreviewRenderKind(t *testing.T) {
+	require.Equal(t, "markdown", TextPreviewRenderKind("notes.md"))
+	require.Equal(t, "plain", TextPreviewRenderKind("50. Holy Water.lrc"))
+	require.Equal(t, "plain", TextPreviewRenderKind("cert.pem"))
+}
+
+func TestTextPreviewMimeTypesIsSortedAndMatchesAllowlist(t *testing.T) {
+	types := TextPreviewMimeTypes()
+	require.NotEmpty(t, types)
+	require.True(t, sort.StringsAreSorted(types), "list must be sorted for a stable globalVars value")
+	for _, mt := range types {
+		require.True(t, IsTextPreviewable(mt), mt)
+	}
+	require.Contains(t, types, "application/json")
+}

frontend/src/components/files/Icon.vue

@@ -53,7 +53,7 @@ import {
   storeThumbnailBlob,
 } from "@/utils/cache/imageCache.ts";
 import { queuedFetchPreview } from "@/utils/previewRequests.ts";
-import { isTextPreviewableName, languageFromPath, MIN_TEXT_PREVIEW_WIDTH_PX } from "@/utils/textPreview.ts";
+import { isTextPreviewableType, languageFromPath, MIN_TEXT_PREVIEW_WIDTH_PX } from "@/utils/textPreview.ts";
 
 const props = withDefaults(
   defineProps<{
@@ -226,7 +226,7 @@ const shouldUse3DPreview = computed(() => {
 
 /** True when the filename has an extension the text preview endpoint supports. */
 const isTextPreviewable = computed(
-  () => props.mimetype !== "directory" && isTextPreviewableName(props.filename),
+  () => props.mimetype !== "directory" && isTextPreviewableType(props.mimetype),
 );
 
 /** Extension used for syntax highlighting and the CSV/TSV delimiter. */

frontend/src/components/files/ListingItem.vue

@@ -98,7 +98,7 @@ import { globalVars } from "@/utils/constants";
 import downloadFiles from "@/utils/download";
 import { getHumanReadableFilesize } from "@/utils/filesizes";
 import { getKindKey } from "@/utils/mimetype";
-import { isTextPreviewableName } from "@/utils/textPreview";
+import { isTextPreviewableType } from "@/utils/textPreview";
 import { hasCachedThumbnailBlob } from "@/utils/cache/imageCache.ts";
 import { formatDuration } from "@/utils/files.js";
 import { getObjectProperty } from '@/utils/object.js';
@@ -383,7 +383,7 @@ export default {
       }
       // Only text-previewable names have a preview; other items must never build a URL
       // (a DuplicateFinder row can pass a text-like name with no source).
-      if (!isTextPreviewableName(this.name)) {
+      if (!isTextPreviewableType(this.type)) {
         return "";
       }
       let previewPath;

frontend/src/components/prompts/Delete.vue

@@ -83,7 +83,7 @@ import { useListingVirtualization } from "@/composables/useListingVirtualization
 import url from "@/utils/url";
 import { removeFromFolderLists } from "@/utils/cache/listingCache.ts";
 
-interface DeleteItem {
+export interface DeleteItem {
   source?: string;
   path: string;
   type?: string;

frontend/src/utils/textPreview.test.ts

@@ -1,9 +1,34 @@
 import { afterEach, describe, expect, it, vi } from "vitest";
+
+// The backend serves the text allowlist through globalVars (backend/internal/web/static.go).
+const { globalsMock } = vi.hoisted(() => ({
+  globalsMock: {
+    textPreviewMimeTypes: [
+      "application/json",
+      "application/yaml",
+      "application/x-yaml",
+      "application/sql",
+      "application/x-sql",
+      "application/x-sh",
+      "application/x-php",
+      "application/x-powershell",
+      "application/x-tex",
+      "application/toml",
+      "application/x-ruby",
+    ] as string[],
+  },
+}));
+
+vi.mock("@/utils/constants.js", async (importOriginal) => ({
+  ...(await importOriginal<object>()),
+  globalVars: globalsMock,
+}));
+
 import {
   clearTextPreviewCache,
   fetchTextPreview,
   getRenderedTextPreview,
-  isTextPreviewableName,
+  isTextPreviewableType,
   languageFromPath,
   languageFromPreviewUrl,
   MIN_TEXT_PREVIEW_WIDTH_PX,
@@ -33,12 +58,34 @@ describe("languageFromPath", () => {
   });
 });
 
-describe("isTextPreviewableName", () => {
-  it("is true for extensions in the backend kind map", () => {
-    // The vitest setup stubs globalVars.textPreviewExtensions.
-    expect(isTextPreviewableName("notes.md")).toBe(true);
-    expect(isTextPreviewableName("image.png")).toBe(false);
-    expect(isTextPreviewableName("noext")).toBe(false);
+describe("isTextPreviewableType", () => {
+  it("is true for text/* mimetypes, with or without parameters", () => {
+    for (const mt of ["text/markdown", "text/lyrics", "text/plain; charset=utf-8", "text/x-go"]) {
+      expect(isTextPreviewableType(mt), mt).toBe(true);
+    }
+  });
+
+  it("is true for text-extension mimetypes that are not text/*", () => {
+    for (const mt of ["application/json", "application/yaml", "application/sql", "application/x-sh", "application/x-php", "application/x-powershell", "application/x-tex"]) {
+      expect(isTextPreviewableType(mt), mt).toBe(true);
+    }
+  });
+
+  it("follows the allowlist served in globalVars", () => {
+    const original = globalsMock.textPreviewMimeTypes;
+    try {
+      globalsMock.textPreviewMimeTypes = ["application/x-custom"];
+      expect(isTextPreviewableType("application/x-custom")).toBe(true);
+      expect(isTextPreviewableType("application/json")).toBe(false);
+    } finally {
+      globalsMock.textPreviewMimeTypes = original;
+    }
+  });
+
+  it("is false for non-text mimetypes and missing types", () => {
+    for (const mt of ["application/x-sqlite3", "application/postscript", "application/wasm", "application/backup", "application/x-msdownload", "application/octet-stream", "image/svg+xml", "image/png", "directory", "", null, undefined]) {
+      expect(isTextPreviewableType(mt), String(mt)).toBe(false);
+    }
   });
 });
 

frontend/src/utils/textPreview.ts

@@ -1,5 +1,5 @@
-import { state } from "@/store/index.ts";
 import { globalVars } from "@/utils/constants.js";
+import { state } from "@/store/index.ts";
 import type { TextPreviewPayload } from "@/utils/textPreviewRender.ts";
 
 // Text previews are small (about 16KB), so the frontend keeps a bounded in-memory cache.
@@ -27,23 +27,29 @@ export function languageFromPath(path: string | null | undefined): string | null
   return name.slice(dot + 1).toLowerCase();
 }
 
-/**
- * Every extension the text preview endpoint supports, from the backend's kind map.
- * Built once per page rather than once per listing item.
- */
-let textPreviewExtSet: Set<string> | null = null;
-export function getTextPreviewExtensions(): Set<string> {
-  if (textPreviewExtSet === null) {
-    const groups = (globalVars.textPreviewExtensions ?? {}) as Record<string, string[]>;
-    textPreviewExtSet = new Set(Object.values(groups).flat());
+// Non-text/* mimetypes (JSON, YAML, SQL, shell, ...) served by the backend in globalVars.
+// The backend is the single source of truth; the Set is rebuilt only when the served array changes.
+let allowlistSource: string[] | undefined;
+let allowlistSet = new Set<string>();
+
+function textPreviewMimeTypes(): Set<string> {
+  const source = globalVars?.textPreviewMimeTypes as string[] | undefined;
+  if (source !== allowlistSource) {
+    allowlistSource = source;
+    allowlistSet = new Set(source ?? []);
   }
-  return textPreviewExtSet;
+  return allowlistSet;
 }
 
-/** True when the filename has an extension the text preview endpoint supports. */
-export function isTextPreviewableName(filename: string | null | undefined): boolean {
-  const ext = languageFromPath(filename);
-  return ext !== null && getTextPreviewExtensions().has(ext);
+/**
+ * True when an item's mimetype is text/* or on the backend's text allowlist. The backend uses
+ * the same rule, so an item the listing marks as text is the one the text preview endpoint
+ * renders. Binary types such as sqlite, postscript, wasm and backup never reach the endpoint.
+ */
+export function isTextPreviewableType(mimetype: string | null | undefined): boolean {
+  // split always yields at least one element; the ?? "" satisfies noUncheckedIndexedAccess.
+  const base = (mimetype ?? "").split(";")[0] ?? "";
+  return base.startsWith("text/") || textPreviewMimeTypes().has(base);
 }
 
 // Text fetches are queued so a folder full of text files does not fire dozens of

frontend/tests/mocks/setup.js

@@ -86,14 +86,6 @@ vi.mock('@/utils/constants', () => {
   return {
     globalVars: {
       baseURL: "/files/",
-      textPreviewExtensions: {
-        markdown: ["md"],
-        code: ["go", "js", "ts"],
-        csv: ["csv", "tsv"],
-        html: ["html"],
-        plain: ["txt"],
-        rtf: ["rtf"],
-      },
     },
     baseURL: "/files/",
   };

frontend/vite.config.ts

@@ -8,7 +8,6 @@ import stripLegacyCSS from "./scripts/postcss-strip-legacy.ts";
 import protectTemplateStyles from "./scripts/vite-protect-template-styles.ts";
 
 const isDevBuild = process.env.DEV_BUILD === "true";
-const backendWebDist = path.resolve(import.meta.dirname, "../backend/internal/web/dist");
 // Docker builds skip vue-tsc here; CI type-checks in regular-tests.yaml.
 const skipTypecheck = process.env.SKIP_TYPECHECK === "1";
 
@@ -122,7 +121,6 @@ export default defineConfig(({ command }) => {
     base: "",
     define,
     build: {
-      outDir: backendWebDist,
       emptyOutDir: true,
       // Optimize for watch mode stability
       watch: isDevBuild ? {

makefile

@@ -19,7 +19,7 @@ backend_dev_tool = $$(cd $(BACKEND_BUILD) && go tool -n $(1))
 
 .SILENT:
 
-.PHONY: setup update build build-docker build-docker-media build-backend build-frontend dev run generate-docs
+.PHONY: setup update build build-docker build-docker-media build-backend build-frontend embed-frontend dev run generate-docs
 .PHONY: lint-frontend lint-backend lint test test-backend test-frontend check-all
 .PHONY: check-translations sync-translations test-playwright test-playwright-project test-playwright-performance playwright-base playwright-perf-base perf-check perf-smoke perf-baseline perf-dashboard run-proxy screenshots
 .PHONY: check-icons generate-icons sync-icons
@@ -52,7 +52,13 @@ build-docker-slim:
 build-docker-media:
 	DOCKER_BUILDKIT=1 docker build --build-arg="VERSION=testing" --build-arg="REVISION=n/a" -t gtstef/filebrowser-media -f _docker/Dockerfile.media .
 
-build-backend:
+embed-frontend:
+	@test -d frontend/dist || (echo "Missing frontend/dist; run 'make build-frontend' first." >&2 && exit 1)
+	mkdir -p backend/internal/web/dist
+	find backend/internal/web/dist -mindepth 1 ! -name '.gitkeep' ! -name 'config.generated.yaml' -delete
+	cp -r frontend/dist/. backend/internal/web/dist/
+
+build-backend: embed-frontend
 	@echo "Building backend..."
 	cd backend && go build -o filebrowser --ldflags="-w -s -X 'github.com/gtsteffaniak/filebrowser/backend/internal/version.CommitSHA=testingCommit' -X 'github.com/gtsteffaniak/filebrowser/backend/internal/version.Version=testing'"
 	@echo "✓ Backend built successfully"
@@ -64,6 +70,7 @@ dev: generate-docs generate-icons
 	bash ./scripts/dev.sh
 
 run: build-frontend generate-docs
+	$(MAKE) embed-frontend
 	cd backend && $(call backend_dev_tool,swag) init --output swagger/docs
 	@if [ "$$(uname)" = "Darwin" ]; then \
 		sed -i '' '/func init/,+3d' backend/swagger/docs/docs.go; \
@@ -138,7 +145,7 @@ PLAYWRIGHT_PROJECTS := sharing settings noauth general jwt proxy previews oidc n
 #   make test-playwright-project PROJECT=previews
 # or:
 #   make test-playwright PROJECT=previews
-test-playwright: build-frontend
+test-playwright: build-frontend embed-frontend
 	cd backend && GOOS=linux go build -o filebrowser .
 ifeq ($(PROJECT),)
 	$(foreach p,$(PLAYWRIGHT_PROJECTS),docker build -t filebrowser-playwright-tests -f _docker/Dockerfile.playwright-$(p) . ;)
@@ -166,7 +173,7 @@ playwright-perf-base:
 		--build-arg PLAYWRIGHT_BROWSERS="$(PERF_PLAYWRIGHT_BROWSERS)" \
 		-f _docker/Dockerfile.playwright-perf-base .
 
-test-playwright-performance: build-frontend
+test-playwright-performance: build-frontend embed-frontend
 	cd backend && GOOS=linux go build -o filebrowser .
 	DOCKER_BUILDKIT=1 docker build --target ci -t filebrowser-playwright-performance \
 		-f _docker/Dockerfile.playwright-performance .
@@ -182,7 +189,9 @@ PERF_BROWSERS ?= chromium,firefox,webkit
 # Only chromium feeds the CI baseline; the others are advisory insight.
 perf-check:
 ifndef PERF_SKIP_BUILD
-	$(MAKE) build-frontend
+	$(MAKE) build-frontend embed-frontend
+else
+	$(MAKE) embed-frontend
 endif
 	cd backend && GOOS=linux go build -o filebrowser .
 ifndef PERF_SKIP_PLAYWRIGHT_BASE
@@ -213,7 +222,7 @@ perf-dashboard:
 # get version from environment variable, for example
 # cd frontend && npm i @playwright/test && npx playwright install --with-deps chromium
 # make PLAYWRIGHT_TEST=settings test-playwright-ui
-test-playwright-ui: build-frontend
+test-playwright-ui: build-frontend embed-frontend
 	docker stop local-playwright-tests || true
 	docker rm local-playwright-tests || true
 	rm -rf _docker/src/tmp/ || true && mkdir -p _docker/src/tmp/
@@ -234,7 +243,7 @@ run-jwt: build-frontend
 # optional: install playwright locally
 # once local playwright server is running, you can also watch the tests interactively with:
 # cd frontend && npx playwright test --project dark-screenshots --ui
-screenshots: build-frontend
+screenshots: build-frontend embed-frontend
 	cd backend && GOOS=linux go build -o filebrowser --ldflags="-w -s -X 'github.com/gtsteffaniak/filebrowser/backend/internal/version.Version=latest'" .
 	@echo "Running screenshots..."
 	cd _docker && docker compose down && docker compose up --build local-playwright-screenshots