fix #164: avoid slashes in file loader file names

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+* Fix slash characters in file loader ([#164](https://github.com/evanw/esbuild/pull/164))
+
+    This fixes a bug where the base64-encoded hash included in the file name could sometimes contain a `/` character. The fix is to use the base64 character set for URL-encoding, which replaces the `/` character with a `_` character.
+
 ## 0.4.4
 
 * Fix optional chaining with TypeScript operators ([#168](https://github.com/evanw/esbuild/issues/168))

internal/bundler/bundler.go

@@ -184,7 +184,7 @@ func parseFile(args parseArgs) {
 		// but different contents from colliding
 		bytes := []byte(source.Contents)
 		hashBytes := sha1.Sum(bytes)
-		hash := base64.StdEncoding.EncodeToString(hashBytes[:])[:8]
+		hash := base64.URLEncoding.EncodeToString(hashBytes[:])[:8]
 		baseName = baseName[:len(baseName)-len(extension)] + "." + hash + extension
 
 		// Determine the destination folder

internal/bundler/bundler_test.go

@@ -2764,7 +2764,9 @@ func TestLoaderFile(t *testing.T) {
 			"/entry.js": `
 				console.log(require('./test.svg'))
 			`,
-			"/test.svg": "<svg></svg>",
+
+			// Use an SVG string that has a base64-encoded SHA1 has with a "/" in it
+			"/test.svg": "<svg>$</svg>",
 		},
 		entryPaths: []string{"/entry.js"},
 		parseOptions: parser.ParseOptions{
@@ -2779,10 +2781,10 @@ func TestLoaderFile(t *testing.T) {
 			},
 		},
 		expected: map[string]string{
-			"/out/test.ntXZxVw0.svg": "<svg></svg>",
+			"/out/test.1HOBn_hi.svg": "<svg>$</svg>",
 			"/out/entry.js": `// /test.svg
 var require_test = __commonJS((exports, module) => {
-  module.exports = "test.ntXZxVw0.svg";
+  module.exports = "test.1HOBn_hi.svg";
 });
 
 // /entry.js