refactor: simplify binary detection with filetype

  - replace gofile mime detection with filetype matches check
  - remove custom isBinaryMIME helper and associated tests
  - update module dependencies to use github.com/h2non/filetype

Author: jcouture

go.mod

@@ -7,7 +7,7 @@ require github.com/fatih/color v1.19.0
 require github.com/rs/zerolog v1.35.0
 
 require (
-	github.com/shirou/gofile v0.0.0-20260314143841-7dc06be96404
+	github.com/h2non/filetype v1.1.3
 	github.com/spf13/pflag v1.0.10
 )
 

go.sum

@@ -1,13 +1,13 @@
 github.com/fatih/color v1.19.0 h1:Zp3PiM21/9Ld6FzSKyL5c/BULoe/ONr9KlbYVOfG8+w=
 github.com/fatih/color v1.19.0/go.mod h1:zNk67I0ZUT1bEGsSGyCZYZNrHuTkJJB+r6Q9VuMi0LE=
+github.com/h2non/filetype v1.1.3 h1:FKkx9QbD7HR/zjK1Ia5XiBsq9zdLi5Kf3zGyFTAFkGg=
+github.com/h2non/filetype v1.1.3/go.mod h1:319b3zT68BvV+WRj7cwy856M2ehB3HqNOt6sy1HndBY=
 github.com/mattn/go-colorable v0.1.14 h1:9A9LHSqF/7dyVVX6g0U9cwm9pG3kP9gSzcuIPHPsaIE=
 github.com/mattn/go-colorable v0.1.14/go.mod h1:6LmQG8QLFO4G5z1gPvYEzlUgJ2wF+stgPZH1UqBm1s8=
 github.com/mattn/go-isatty v0.0.21 h1:xYae+lCNBP7QuW4PUnNG61ffM4hVIfm+zUzDuSzYLGs=
 github.com/mattn/go-isatty v0.0.21/go.mod h1:ZXfXG4SQHsB/w3ZeOYbR0PrPwLy+n6xiMrJlRFqopa4=
 github.com/rs/zerolog v1.35.0 h1:VD0ykx7HMiMJytqINBsKcbLS+BJ4WYjz+05us+LRTdI=
 github.com/rs/zerolog v1.35.0/go.mod h1:EjML9kdfa/RMA7h/6z6pYmq1ykOuA8/mjWaEvGI+jcw=
-github.com/shirou/gofile v0.0.0-20260314143841-7dc06be96404 h1:FSesQzaVDGqNiF1pyQ8QTNpRZrBjXq+AQijCoEqY1Gw=
-github.com/shirou/gofile v0.0.0-20260314143841-7dc06be96404/go.mod h1:5R2Lq6rCwzvUkQLMyzYn2lkwhkXgrlgz803ZRWViHdw=
 github.com/spf13/pflag v1.0.10 h1:4EBh2KAYBwaONj6b2Ye1GiHfwjqyROoF4RwYO+vPwFk=
 github.com/spf13/pflag v1.0.10/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 golang.org/x/sys v0.43.0 h1:Rlag2XtaFTxp19wS8MXlJwTvoh8ArU6ezoyFsMyCTNI=

internal/app/coverage_test.go

@@ -27,52 +27,6 @@ import (
 	"testing"
 )
 
-// --- isBinaryMIME ---
-
-func TestIsBinaryMIME(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		mime string
-		want bool
-	}{
-		{"", false},
-		{"text/plain", false},
-		{"text/html", false},
-		{"application/json", false},
-		{"application/javascript", false},
-		{"application/pdf", true},
-		{"application/octet-stream", true},
-		{"image/png", true},
-		{"image/jpeg", true},
-		{"image/gif", true},
-		{"image/svg+xml", true},
-		{"audio/mpeg", true},
-		{"video/mp4", true},
-		{"font/ttf", true},
-		{"application/zip", true},
-		{"application/gzip", true},
-		{"application/x-gzip", true},
-		{"application/x-bzip2", true},
-		{"application/x-tar", true},
-		{"application/x-7z-compressed", true},
-		{"application/vnd.rar", true},
-		{"application/java-archive", true},
-		{"application/x-java-class", true},
-		{"application/wasm", true},
-		{"application/x-sqlite3", true},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.mime, func(t *testing.T) {
-			t.Parallel()
-			if got := isBinaryMIME(tt.mime); got != tt.want {
-				t.Fatalf("isBinaryMIME(%q) = %v, want %v", tt.mime, got, tt.want)
-			}
-		})
-	}
-}
-
 // --- Run with invalid format ---
 
 func TestRunInvalidFormat(t *testing.T) {

internal/app/run.go

@@ -27,14 +27,13 @@ import (
 	"io"
 	"runtime"
 	"sort"
-	"strings"
 	"time"
 
+	"github.com/h2non/filetype"
 	"github.com/jcouture/ghostscan/internal/filesystem"
 	"github.com/jcouture/ghostscan/internal/finding"
 	"github.com/jcouture/ghostscan/internal/report"
 	"github.com/jcouture/ghostscan/internal/scan"
-	"github.com/shirou/gofile"
 )
 
 type Options struct {
@@ -110,12 +109,8 @@ func Run(ctx context.Context, opts Options) (Result, error) {
 		now = time.Now
 	}
 
-	identifier, err := gofile.New(gofile.Options{MimeType: true})
-	if err != nil {
-		return Result{}, fmt.Errorf("initialize binary identifier: %w", err)
-	}
 	binaryCheck := func(buf []byte) bool {
-		return isBinaryMIME(identifier.IdentifyBuffer(buf))
+		return filetype.Matches(buf)
 	}
 
 	runStart := now().UTC()
@@ -325,29 +320,6 @@ func reportErrors(scanErrors []scanError) []report.ErrorEntry {
 	return items
 }
 
-func isBinaryMIME(mimeType string) bool {
-	if mimeType == "" {
-		return false
-	}
-	return strings.HasPrefix(mimeType, "image/") ||
-		strings.HasPrefix(mimeType, "audio/") ||
-		strings.HasPrefix(mimeType, "video/") ||
-		strings.HasPrefix(mimeType, "font/") ||
-		mimeType == "application/pdf" ||
-		mimeType == "application/octet-stream" ||
-		mimeType == "application/zip" ||
-		mimeType == "application/gzip" ||
-		mimeType == "application/x-gzip" ||
-		mimeType == "application/x-bzip2" ||
-		mimeType == "application/x-tar" ||
-		mimeType == "application/x-7z-compressed" ||
-		mimeType == "application/vnd.rar" ||
-		mimeType == "application/java-archive" ||
-		mimeType == "application/x-java-class" ||
-		mimeType == "application/wasm" ||
-		mimeType == "application/x-sqlite3"
-}
-
 func mapSkipReason(reason filesystem.EligibilityReason) string {
 	switch reason {
 	case filesystem.EligibilityReasonBinaryNUL, filesystem.EligibilityReasonBinaryMagic: