fix #364: "chmod +x" for hashbang files

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+* Mark output files with a hashbang as executable ([#364](https://github.com/evanw/esbuild/issues/364))
+
+    Output files that start with a hashbang line such as `#!/usr/bin/env node` will now automatically be marked as executable. This lets you run them directly in a Unix-like shell without using the `node` command.
+
 ## 0.6.34
 
 * Fix parsing of `type;` statements followed by an identifier in TypeScript ([#377](https://github.com/evanw/esbuild/pull/377))

internal/bundler/bundler.go

@@ -619,6 +619,8 @@ type OutputFile struct {
 	// about this file in JSON format. This is a partial JSON file that will be
 	// fully assembled later.
 	jsonMetadataChunk []byte
+
+	IsExecutable bool
 }
 
 type lineColumnOffset struct {

internal/bundler/linker.go

@@ -3023,6 +3023,7 @@ func (c *linkerContext) generateChunk(chunk *chunkInfo) func([]ast.ImportRecord)
 			newline = ""
 		}
 		newlineBeforeComment := false
+		isExecutable := false
 
 		if chunk.isEntryPoint {
 			file := &c.files[chunk.sourceIndex]
@@ -3033,6 +3034,7 @@ func (c *linkerContext) generateChunk(chunk *chunkInfo) func([]ast.ImportRecord)
 				prevOffset.advanceString(hashbang)
 				j.AddString(hashbang)
 				newlineBeforeComment = true
+				isExecutable = true
 			}
 
 			// Add the top-level directive if present
@@ -3262,6 +3264,7 @@ func (c *linkerContext) generateChunk(chunk *chunkInfo) func([]ast.ImportRecord)
 			AbsPath:           c.fs.Join(c.options.AbsOutputDir, chunk.relPath()),
 			Contents:          jsContents,
 			jsonMetadataChunk: jsonMetadataChunk,
+			IsExecutable:      isExecutable,
 		})
 		return results
 	}

pkg/api/api_impl.go

@@ -522,49 +522,55 @@ func buildImpl(buildOpts BuildOptions) BuildResult {
 
 			// Stop now if there were errors
 			if !log.HasErrors() {
-				// Return the results
-				outputFiles = make([]OutputFile, len(results))
-				for i, result := range results {
-					if options.WriteToStdout {
-						result.AbsPath = "<stdout>"
-					}
-					outputFiles[i] = OutputFile{
-						Path:     result.AbsPath,
-						Contents: result.Contents,
-					}
-				}
-
 				if buildOpts.Write {
 					// Special-case writing to stdout
 					if options.WriteToStdout {
-						if len(outputFiles) != 1 {
+						if len(results) != 1 {
 							log.AddError(nil, logger.Loc{}, fmt.Sprintf(
-								"Internal error: did not expect to generate %d files when writing to stdout", len(outputFiles)))
-						} else if _, err := os.Stdout.Write(outputFiles[0].Contents); err != nil {
+								"Internal error: did not expect to generate %d files when writing to stdout", len(results)))
+						} else if _, err := os.Stdout.Write(results[0].Contents); err != nil {
 							log.AddError(nil, logger.Loc{}, fmt.Sprintf(
 								"Failed to write to stdout: %s", err.Error()))
 						}
 					} else {
 						// Write out files in parallel
 						waitGroup := sync.WaitGroup{}
-						waitGroup.Add(len(outputFiles))
-						for _, outputFile := range outputFiles {
-							go func(outputFile OutputFile) {
+						waitGroup.Add(len(results))
+						for _, result := range results {
+							go func(result bundler.OutputFile) {
 								fs.BeforeFileOpen()
 								defer fs.AfterFileClose()
-								if err := os.MkdirAll(filepath.Dir(outputFile.Path), 0755); err != nil {
+								if err := os.MkdirAll(filepath.Dir(result.AbsPath), 0755); err != nil {
 									log.AddError(nil, logger.Loc{}, fmt.Sprintf(
 										"Failed to create output directory: %s", err.Error()))
-								} else if err := ioutil.WriteFile(outputFile.Path, outputFile.Contents, 0644); err != nil {
-									log.AddError(nil, logger.Loc{}, fmt.Sprintf(
-										"Failed to write to output file: %s", err.Error()))
+								} else {
+									var mode os.FileMode = 0644
+									if result.IsExecutable {
+										mode = 0755
+									}
+									if err := ioutil.WriteFile(result.AbsPath, result.Contents, mode); err != nil {
+										log.AddError(nil, logger.Loc{}, fmt.Sprintf(
+											"Failed to write to output file: %s", err.Error()))
+									}
 								}
 								waitGroup.Done()
-							}(outputFile)
+							}(result)
 						}
 						waitGroup.Wait()
 					}
 				}
+
+				// Return the results
+				outputFiles = make([]OutputFile, len(results))
+				for i, result := range results {
+					if options.WriteToStdout {
+						result.AbsPath = "<stdout>"
+					}
+					outputFiles[i] = OutputFile{
+						Path:     result.AbsPath,
+						Contents: result.Contents,
+					}
+				}
 			}
 		}
 	}