fix #785: avoid absolute paths for disabled files

CHANGELOG.md

@@ -72,6 +72,12 @@
 
     This caused a problem with the synchronous JavaScript API calls which run the esbuild child process in a single-response mode. The ping message was interpreted as a second response and tripped up the message protocol. Pings are only useful for the asynchronous API calls. Running the pings during synchronous API calls was unintentional. With this release pings are no longer run for synchronous API calls so this regression should be fixed.
 
+* Remove absolute paths for disabled files from source maps ([#785](https://github.com/evanw/esbuild/issues/785))
+
+    Files can be ignored (i.e. set to empty) using the [`browser` field in `package.json`](https://github.com/defunctzombie/package-browser-field-spec/tree/4f296871cee64e60124841c06c06511885152f19#ignore-a-module). Specifically, you can set the `browser` field to a map where the key is the module name and the value is `false`. This is a convention followed by several bundlers including esbuild.
+
+    Previously ignoring a file caused that file's path to appear as an absolute path in any generated source map. This is problematic because it means different source maps will be generated on different systems, since the absolute path contains system-specific directory information. Now esbuild will treat these paths the same way it treats other paths and will put a relative path in the source map.
+
 ## 0.8.43
 
 * Support the `XDG_CACHE_HOME` environment variable ([#757](https://github.com/evanw/esbuild/issues/757))

internal/bundler/bundler.go

@@ -774,6 +774,11 @@ func runOnLoadPlugins(
 		}
 	}
 
+	// Force disabled modules to be empty
+	if source.KeyPath.IsDisabled() {
+		return loaderPluginResult{loader: config.LoaderJS}, true
+	}
+
 	// Read normal modules from disk
 	if source.KeyPath.Namespace == "file" {
 		if contents, err := fsCache.ReadFile(fs, source.KeyPath.Text); err == nil {
@@ -793,11 +798,6 @@ func runOnLoadPlugins(
 		}
 	}
 
-	// Force disabled modules to be empty
-	if source.KeyPath.Namespace == resolver.BrowserFalseNamespace {
-		return loaderPluginResult{loader: config.LoaderJS}, true
-	}
-
 	// Otherwise, fail to load the path
 	return loaderPluginResult{loader: config.LoaderNone}, true
 }

internal/bundler/linker.go

@@ -2224,7 +2224,7 @@ func (c *linkerContext) advanceImportTracker(tracker importTracker) (importTrack
 
 	// Is this a disabled file?
 	otherSourceIndex := *record.SourceIndex
-	if c.files[otherSourceIndex].source.KeyPath.Namespace == resolver.BrowserFalseNamespace {
+	if c.files[otherSourceIndex].source.KeyPath.IsDisabled() {
 		return importTracker{sourceIndex: otherSourceIndex, importRef: js_ast.InvalidRef}, importDisabled, nil
 	}
 

internal/bundler/snapshots/snapshots_packagejson.txt

@@ -50,7 +50,7 @@ var index;
 ================================================================================
 TestPackageJsonBrowserMapModuleDisabled
 ---------- /Users/user/project/out.js ----------
-// empty:/Users/user/project/node_modules/node-pkg/index.js
+// (disabled):/Users/user/project/node_modules/node-pkg/index.js
 var require_node_pkg = __commonJS(() => {
 });
 
@@ -113,7 +113,7 @@ console.log(import_demo_pkg.default());
 ================================================================================
 TestPackageJsonBrowserMapNativeModuleDisabled
 ---------- /Users/user/project/out.js ----------
-// empty:fs
+// (disabled):fs
 var require_fs = __commonJS(() => {
 });
 
@@ -132,7 +132,7 @@ console.log(import_demo_pkg.default());
 ================================================================================
 TestPackageJsonBrowserMapRelativeDisabled
 ---------- /Users/user/project/out.js ----------
-// empty:/Users/user/project/node_modules/demo-pkg/util-node.js
+// (disabled):Users/user/project/node_modules/demo-pkg/util-node.js
 var require_util_node = __commonJS(() => {
 });
 

internal/logger/logger.go

@@ -129,10 +129,24 @@ func (a SortableMsgs) Less(i int, j int) bool {
 type Path struct {
 	Text      string
 	Namespace string
+	Flags     PathFlags
+}
+
+type PathFlags uint8
+
+const (
+	// This corresponds to a value of "false' in the "browser" package.json field
+	PathDisabled PathFlags = 1 << iota
+)
+
+func (p Path) IsDisabled() bool {
+	return (p.Flags & PathDisabled) != 0
 }
 
 func (a Path) ComesBeforeInSortedOrder(b Path) bool {
-	return a.Namespace > b.Namespace || (a.Namespace == b.Namespace && a.Text < b.Text)
+	return a.Namespace > b.Namespace ||
+		(a.Namespace == b.Namespace && (a.Text < b.Text ||
+			(a.Text == b.Text && a.Flags < b.Flags)))
 }
 
 // This has a custom implementation instead of using "filepath.Dir/Base/Ext"

internal/resolver/resolver.go

@@ -18,10 +18,6 @@ import (
 	"github.com/evanw/esbuild/internal/logger"
 )
 
-// This namespace is used when a module has been disabled by being mapped to
-// "false" using the "browser" field of "package.json".
-const BrowserFalseNamespace = "empty"
-
 var defaultMainFields = map[config.Platform][]string{
 	// Note that this means if a package specifies "main", "module", and
 	// "browser" then "browser" will win out over "module". This is the
@@ -399,7 +395,7 @@ func (r *resolver) resolveWithoutSymlinks(sourceDir string, importPath string, k
 			if packageJSON := importDirInfo.enclosingBrowserScope.packageJSON; packageJSON.browserNonPackageMap != nil {
 				if remapped, ok := packageJSON.browserNonPackageMap[absPath]; ok {
 					if remapped == nil {
-						return &ResolveResult{PathPair: PathPair{Primary: logger.Path{Text: absPath, Namespace: BrowserFalseNamespace}}}
+						return &ResolveResult{PathPair: PathPair{Primary: logger.Path{Text: absPath, Namespace: "file", Flags: logger.PathDisabled}}}
 					} else if remappedResult, ok := r.resolveWithoutRemapping(importDirInfo.enclosingBrowserScope, *remapped, kind); ok {
 						result = remappedResult
 						checkRelative = false
@@ -452,13 +448,13 @@ func (r *resolver) resolveWithoutSymlinks(sourceDir string, importPath string, k
 					if remapped == nil {
 						// "browser": {"module": false}
 						if absolute, ok := r.loadNodeModules(importPath, kind, sourceDirInfo); ok {
-							absolute.Primary = logger.Path{Text: absolute.Primary.Text, Namespace: BrowserFalseNamespace}
+							absolute.Primary = logger.Path{Text: absolute.Primary.Text, Flags: logger.PathDisabled}
 							if absolute.HasSecondary() {
-								absolute.Secondary = logger.Path{Text: absolute.Secondary.Text, Namespace: BrowserFalseNamespace}
+								absolute.Secondary = logger.Path{Text: absolute.Secondary.Text, Flags: logger.PathDisabled}
 							}
 							return &ResolveResult{PathPair: absolute}
 						} else {
-							return &ResolveResult{PathPair: PathPair{Primary: logger.Path{Text: importPath, Namespace: BrowserFalseNamespace}}}
+							return &ResolveResult{PathPair: PathPair{Primary: logger.Path{Text: importPath, Flags: logger.PathDisabled}}}
 						}
 					} else {
 						// "browser": {"module": "./some-file"}
@@ -489,7 +485,7 @@ func (r *resolver) resolveWithoutSymlinks(sourceDir string, importPath string, k
 			if packageJSON.browserNonPackageMap != nil {
 				if remapped, ok := packageJSON.browserNonPackageMap[path.Text]; ok {
 					if remapped == nil {
-						path.Namespace = BrowserFalseNamespace
+						path.Flags |= logger.PathDisabled
 					} else if remappedResult, ok := r.resolveWithoutRemapping(resultDirInfo.enclosingBrowserScope, *remapped, kind); ok {
 						*path = remappedResult.Primary
 					} else {
@@ -522,11 +518,13 @@ func (r *resolver) PrettyPath(path logger.Path) string {
 		// These should be platform-independent so our output doesn't depend on which
 		// operating system it was run. Replace Windows backward slashes with standard
 		// forward slashes.
-		return strings.ReplaceAll(path.Text, "\\", "/")
+		path.Text = strings.ReplaceAll(path.Text, "\\", "/")
+	} else if path.Namespace != "" {
+		path.Text = fmt.Sprintf("%s:%s", path.Namespace, path.Text)
 	}
 
-	if path.Namespace != "" {
-		return fmt.Sprintf("%s:%s", path.Namespace, path.Text)
+	if path.IsDisabled() {
+		path.Text = "(disabled):" + path.Text
 	}
 
 	return path.Text
@@ -1302,7 +1300,7 @@ func (r *resolver) loadNodeModules(path string, kind ast.ImportKind, dirInfo *di
 				if packageJSON := importDirInfo.enclosingBrowserScope.packageJSON; packageJSON.browserNonPackageMap != nil {
 					if remapped, ok := packageJSON.browserNonPackageMap[absPath]; ok {
 						if remapped == nil {
-							return PathPair{Primary: logger.Path{Text: absPath, Namespace: BrowserFalseNamespace}}, true
+							return PathPair{Primary: logger.Path{Text: absPath, Namespace: "file", Flags: logger.PathDisabled}}, true
 						} else if remappedResult, ok := r.resolveWithoutRemapping(importDirInfo.enclosingBrowserScope, *remapped, kind); ok {
 							return remappedResult, true
 						}

scripts/js-api-tests.js

@@ -242,6 +242,27 @@ let buildTests = {
     assert.strictEqual(json.sourcesContent, void 0)
   },
 
+  async sourceMapWithDisabledFile({ esbuild, testDir }) {
+    const input = path.join(testDir, 'in.js')
+    const disabled = path.join(testDir, 'disabled.js')
+    const packageJSON = path.join(testDir, 'package.json')
+    const output = path.join(testDir, 'out.js')
+    const content = 'exports.foo = require("./disabled")'
+    await writeFileAsync(input, content)
+    await writeFileAsync(disabled, 'module.exports = 123')
+    await writeFileAsync(packageJSON, `{"browser": {"./disabled.js": false}}`)
+    await esbuild.build({ entryPoints: [input], outfile: output, sourcemap: true, bundle: true })
+    const result = require(output)
+    assert.strictEqual(result.foo, void 0)
+    const resultMap = await readFileAsync(output + '.map', 'utf8')
+    const json = JSON.parse(resultMap)
+    assert.strictEqual(json.version, 3)
+    assert.strictEqual(json.sources[0], path.basename(disabled))
+    assert.strictEqual(json.sources[1], path.basename(input))
+    assert.strictEqual(json.sourcesContent[0], '')
+    assert.strictEqual(json.sourcesContent[1], content)
+  },
+
   async resolveExtensionOrder({ esbuild, testDir }) {
     const input = path.join(testDir, 'in.js');
     const inputBare = path.join(testDir, 'module.js')