special-case "index" in name-from-path

internal/ast/ast.go

@@ -1,7 +1,6 @@
 package ast
 
 import (
-	"path"
 	"strings"
 )
 
@@ -1259,12 +1258,53 @@ func MergeSymbols(symbols SymbolMap, old Ref, new Ref) Ref {
 	return new
 }
 
-func GenerateNonUniqueNameFromPath(text string) string {
+// This has a custom implementation instead of using "filepath.Base" because it
+// should work the same on Unix and Windows. These names end up in the generated
+// output and the generated output should not depend on the OS.
+func platformIndependentPathDirAndBaseWithoutExt(path string) (string, string) {
+	dir := ""
+	for {
+		i := strings.LastIndexAny(path, "/\\")
+		if i < 0 {
+			break
+		}
+		if i+1 != len(path) {
+			dir = path[:i]
+			path = path[i+1:]
+			break
+		}
+		path = path[:i]
+	}
+	if dot := strings.LastIndexByte(path, '.'); dot >= 0 {
+		path = path[:dot]
+	}
+	return dir, path
+}
+
+// For readability, the names of certain automatically-generated symbols are
+// derived from the file name. For example, instead of the CommonJS wrapper for
+// a file being called something like "require273" it can be called something
+// like "require_react" instead. This function generates the part of these
+// identifiers that's specific to the file path. It can take both an absolute
+// path (OS-specific) and a path in the source code (OS-independent).
+//
+// Note that these generated names do not at all relate to the correctness of
+// the code as far as avoiding symbol name collisions. These names still go
+// through the renaming logic that all other symbols go through to avoid name
+// collisions.
+func GenerateNonUniqueNameFromPath(path string) string {
 	// Get the file name without the extension
-	base := path.Base(text)
-	lastDot := strings.LastIndexByte(base, '.')
-	if lastDot >= 0 {
-		base = base[:lastDot]
+	dir, base := platformIndependentPathDirAndBaseWithoutExt(path)
+
+	// If the name is "index", use the directory name instead. This is because
+	// many packages in npm use the file name "index.js" because it triggers
+	// node's implicit module resolution rules that allows you to import it by
+	// just naming the directory.
+	if base == "index" {
+		_, dirBase := platformIndependentPathDirAndBaseWithoutExt(dir)
+		if dirBase != "" {
+			base = dirBase
+		}
 	}
 
 	// Convert it to an ASCII identifier

internal/ast/ast_test.go

@@ -0,0 +1,23 @@
+package ast
+
+import "testing"
+
+func assertEqual(t *testing.T, a interface{}, b interface{}) {
+	if a != b {
+		t.Fatalf("%s != %s", a, b)
+	}
+}
+
+func TestGenerateNonUniqueNameFromPath(t *testing.T) {
+	assertEqual(t, GenerateNonUniqueNameFromPath("<stdin>"), "stdin")
+	assertEqual(t, GenerateNonUniqueNameFromPath("foo/bar"), "bar")
+	assertEqual(t, GenerateNonUniqueNameFromPath("foo/bar.js"), "bar")
+	assertEqual(t, GenerateNonUniqueNameFromPath("foo/bar.min.js"), "bar_min")
+	assertEqual(t, GenerateNonUniqueNameFromPath("trailing//slashes//"), "slashes")
+	assertEqual(t, GenerateNonUniqueNameFromPath("path/with/spaces in name.js"), "spaces_in_name")
+	assertEqual(t, GenerateNonUniqueNameFromPath("path\\on\\windows.js"), "windows")
+	assertEqual(t, GenerateNonUniqueNameFromPath("node_modules/demo-pkg/index.js"), "demo_pkg")
+	assertEqual(t, GenerateNonUniqueNameFromPath("node_modules\\demo-pkg\\index.js"), "demo_pkg")
+	assertEqual(t, GenerateNonUniqueNameFromPath("123_invalid_identifier.js"), "invalid_identifier")
+	assertEqual(t, GenerateNonUniqueNameFromPath("emoji 🍕 name.js"), "emoji_name")
+}

internal/bundler/bundler_dce_test.go

@@ -70,13 +70,13 @@ func TestPackageJsonSideEffectsFalseKeepNamedImportCommonJS(t *testing.T) {
 		},
 		expected: map[string]string{
 			"/out.js": `// /Users/user/project/node_modules/demo-pkg/index.js
-var require_index = __commonJS((exports) => {
+var require_demo_pkg = __commonJS((exports) => {
   exports.foo = 123;
   console.log("hello");
 });
 
 // /Users/user/project/src/entry.js
-const demo_pkg = __toModule(require_index());
+const demo_pkg = __toModule(require_demo_pkg());
 console.log(demo_pkg.foo);
 `,
 		},
@@ -110,15 +110,15 @@ func TestPackageJsonSideEffectsFalseKeepStarImportES6(t *testing.T) {
 		},
 		expected: map[string]string{
 			"/out.js": `// /Users/user/project/node_modules/demo-pkg/index.js
-const index_exports = {};
-__export(index_exports, {
+const demo_pkg_exports = {};
+__export(demo_pkg_exports, {
   foo: () => foo
 });
 const foo = 123;
 console.log("hello");
 
 // /Users/user/project/src/entry.js
-console.log(index_exports);
+console.log(demo_pkg_exports);
 `,
 		},
 	})
@@ -151,13 +151,13 @@ func TestPackageJsonSideEffectsFalseKeepStarImportCommonJS(t *testing.T) {
 		},
 		expected: map[string]string{
 			"/out.js": `// /Users/user/project/node_modules/demo-pkg/index.js
-var require_index = __commonJS((exports) => {
+var require_demo_pkg = __commonJS((exports) => {
   exports.foo = 123;
   console.log("hello");
 });
 
 // /Users/user/project/src/entry.js
-const ns = __toModule(require_index());
+const ns = __toModule(require_demo_pkg());
 console.log(ns);
 `,
 		},
@@ -227,13 +227,13 @@ func TestPackageJsonSideEffectsTrueKeepCommonJS(t *testing.T) {
 		},
 		expected: map[string]string{
 			"/out.js": `// /Users/user/project/node_modules/demo-pkg/index.js
-var require_index = __commonJS((exports) => {
+var require_demo_pkg = __commonJS((exports) => {
   exports.foo = 123;
   console.log("hello");
 });
 
 // /Users/user/project/src/entry.js
-const demo_pkg = __toModule(require_index());
+const demo_pkg = __toModule(require_demo_pkg());
 console.log("unused import");
 `,
 		},
@@ -268,7 +268,7 @@ func TestPackageJsonSideEffectsFalseKeepBareImportAndRequireES6(t *testing.T) {
 		},
 		expected: map[string]string{
 			"/out.js": `// /Users/user/project/node_modules/demo-pkg/index.js
-var require_index = __commonJS((exports) => {
+var require_demo_pkg = __commonJS((exports) => {
   __export(exports, {
     foo: () => foo
   });
@@ -277,7 +277,7 @@ var require_index = __commonJS((exports) => {
 });
 
 // /Users/user/project/src/entry.js
-require_index();
+require_demo_pkg();
 console.log("unused import");
 `,
 		},
@@ -312,13 +312,13 @@ func TestPackageJsonSideEffectsFalseKeepBareImportAndRequireCommonJS(t *testing.
 		},
 		expected: map[string]string{
 			"/out.js": `// /Users/user/project/node_modules/demo-pkg/index.js
-var require_index = __commonJS((exports) => {
+var require_demo_pkg = __commonJS((exports) => {
   exports.foo = 123;
   console.log("hello");
 });
 
 // /Users/user/project/src/entry.js
-require_index();
+require_demo_pkg();
 console.log("unused import");
 `,
 		},
@@ -651,10 +651,10 @@ func TestPackageJsonSideEffectsKeepExportDefaultExpr(t *testing.T) {
 		},
 		expected: map[string]string{
 			"/out.js": `// /Users/user/project/node_modules/demo-pkg/index.js
-const index_default = exprWithSideEffects();
+const demo_pkg_default = exprWithSideEffects();
 
 // /Users/user/project/src/entry.js
-console.log(index_default);
+console.log(demo_pkg_default);
 `,
 		},
 	})

internal/bundler/bundler_importstar_test.go

@@ -1974,13 +1974,13 @@ const foo = () => "hi there";
 // /folders/child/index.js
 
 // /folders/index.js
-const index_exports = {};
-__export(index_exports, {
+const folders_exports = {};
+__export(folders_exports, {
   foo: () => foo
 });
 
 // /entry.js
-console.log(JSON.stringify(index_exports));
+console.log(JSON.stringify(folders_exports));
 `,
 		},
 	})