don't use contents for file loader hash

internal/bundler/bundler.go

@@ -7,6 +7,7 @@ import (
 	"mime"
 	"net/http"
 	"sort"
+	"strings"
 	"sync"
 
 	"github.com/evanw/esbuild/internal/ast"
@@ -184,17 +185,10 @@ func parseFile(args parseArgs) {
 		result.file.ignoreIfUnused = true
 
 	case LoaderFile:
-		// Get the file name, making sure to use the "fs" interface so we do the
-		// right thing on Windows (Windows-style paths for the command-line
-		// interface and Unix-style paths for tests, even on Windows)
-		baseName := args.fs.Base(args.absPath)
-
-		// Add a hash to the file name to prevent multiple files with the same name
-		// but different contents from colliding
-		bytes := []byte(source.Contents)
-		hashBytes := sha1.Sum(bytes)
-		hash := base64.URLEncoding.EncodeToString(hashBytes[:])[:8]
-		baseName = baseName[:len(baseName)-len(extension)] + "." + hash + extension
+		// Add a hash to the file name to prevent multiple files with the same base
+		// name from colliding. Avoid using the absolute path to prevent build
+		// output from being different on different machines.
+		baseName := baseNameForAvoidingCollisions(args.fs, args.absPath)
 
 		// Determine the destination folder
 		targetFolder := args.bundleOptions.AbsOutputDir
@@ -218,7 +212,7 @@ func parseFile(args parseArgs) {
 		// the file if the module isn't removed due to tree shaking.
 		result.file.additionalFile = &OutputFile{
 			AbsPath:           args.fs.Join(targetFolder, baseName),
-			Contents:          bytes,
+			Contents:          []byte(source.Contents),
 			jsonMetadataChunk: jsonMetadataChunk,
 		}
 
@@ -231,6 +225,30 @@ func parseFile(args parseArgs) {
 	args.results <- result
 }
 
+func baseNameForAvoidingCollisions(fs fs.FS, absPath string) string {
+	var toHash []byte
+	if relPath, ok := fs.RelativeToCwd(absPath); ok {
+		// Attempt to generate the same base name regardless of what machine or
+		// operating system we're on. We want to avoid absolute paths because they
+		// will have different home directories. We also want to avoid path
+		// separators because they are different on Windows.
+		toHash = []byte(strings.ReplaceAll(relPath, "\\", "/"))
+	} else {
+		// Just use the absolute path if this environment doesn't have a current
+		// directory. This is the case when running tests, for example.
+		toHash = []byte(absPath)
+	}
+
+	// Use "URLEncoding" instead of "StdEncoding" to avoid introducing "/"
+	hashBytes := sha1.Sum(toHash)
+	hash := base64.URLEncoding.EncodeToString(hashBytes[:])[:8]
+
+	// Insert the hash before the extension
+	base := fs.Base(absPath)
+	ext := fs.Ext(absPath)
+	return base[:len(base)-len(ext)] + "." + hash + ext
+}
+
 func ScanBundle(
 	log logging.Log, fs fs.FS, res resolver.Resolver, entryPaths []string,
 	parseOptions parser.ParseOptions, bundleOptions BundleOptions,

internal/bundler/bundler_test.go

@@ -2807,11 +2807,12 @@ func TestLoaderFile(t *testing.T) {
 	expectBundled(t, bundled{
 		files: map[string]string{
 			"/entry.js": `
-				console.log(require('./test.svg'))
+				console.log(require('./test3.svg'))
 			`,
 
-			// Use an SVG string that has a base64-encoded SHA1 has with a "/" in it
-			"/test.svg": "<svg>$</svg>",
+			// "/test3.svg" generates the file name "test3.0sKdZN/F.svg" if the
+			// standard base64 encoding is used instead of the URL base64 encoding
+			"/test3.svg": "<svg></svg>",
 		},
 		entryPaths: []string{"/entry.js"},
 		parseOptions: parser.ParseOptions{
@@ -2826,14 +2827,60 @@ func TestLoaderFile(t *testing.T) {
 			},
 		},
 		expected: map[string]string{
-			"/out/test.1HOBn_hi.svg": "<svg>$</svg>",
-			"/out/entry.js": `// /test.svg
-var require_test = __commonJS((exports, module) => {
-  module.exports = "test.1HOBn_hi.svg";
+			"/out/test3.0sKdZN_F.svg": "<svg></svg>",
+			"/out/entry.js": `// /test3.svg
+var require_test3 = __commonJS((exports, module) => {
+  module.exports = "test3.0sKdZN_F.svg";
 });
 
 // /entry.js
-console.log(require_test());
+console.log(require_test3());
+`,
+		},
+	})
+}
+
+func TestLoaderFileMultipleNoCollision(t *testing.T) {
+	expectBundled(t, bundled{
+		files: map[string]string{
+			"/entry.js": `
+				console.log(
+					require('./a/test.txt'),
+					require('./b/test.txt'),
+				)
+			`,
+
+			// Two files with the same contents but different paths
+			"/a/test.txt": "test",
+			"/b/test.txt": "test",
+		},
+		entryPaths: []string{"/entry.js"},
+		parseOptions: parser.ParseOptions{
+			IsBundling: true,
+		},
+		bundleOptions: BundleOptions{
+			IsBundling:    true,
+			AbsOutputFile: "/dist/out.js",
+			ExtensionToLoader: map[string]Loader{
+				".js":  LoaderJS,
+				".txt": LoaderFile,
+			},
+		},
+		expected: map[string]string{
+			"/dist/test.d-VvEp_S.txt": "test",
+			"/dist/test.pL3kpHJC.txt": "test",
+			"/dist/out.js": `// /a/test.txt
+var require_test = __commonJS((exports, module) => {
+  module.exports = "test.d-VvEp_S.txt";
+});
+
+// /b/test.txt
+var require_test2 = __commonJS((exports, module) => {
+  module.exports = "test.pL3kpHJC.txt";
+});
+
+// /entry.js
+console.log(require_test(), require_test2());
 `,
 		},
 	})