Move common source directory computation to output paths

Author: sheetalkamat

internal/compiler/program.go

@@ -709,89 +709,25 @@ func (p *Program) GetDefaultResolutionModeForFile(sourceFile ast.HasFileName) co
 
 func (p *Program) CommonSourceDirectory() string {
 	p.commonSourceDirectoryOnce.Do(func() {
-		var files []string
-		host := &emitHost{program: p}
-		for _, file := range p.files {
-			if sourceFileMayBeEmitted(file, host, false /*forceDtsEmit*/) {
-				files = append(files, file.FileName())
-			}
-		}
-		p.commonSourceDirectory = getCommonSourceDirectory(
+		p.commonSourceDirectory = outputpaths.GetCommonSourceDirectory(
 			p.Options(),
-			files,
+			func() []string {
+				var files []string
+				host := &emitHost{program: p}
+				for _, file := range p.files {
+					if sourceFileMayBeEmitted(file, host, false /*forceDtsEmit*/) {
+						files = append(files, file.FileName())
+					}
+				}
+				return files
+			},
 			p.GetCurrentDirectory(),
 			p.UseCaseSensitiveFileNames(),
 		)
 	})
 	return p.commonSourceDirectory
 }
 
-func computeCommonSourceDirectoryOfFilenames(fileNames []string, currentDirectory string, useCaseSensitiveFileNames bool) string {
-	var commonPathComponents []string
-	for _, sourceFile := range fileNames {
-		// Each file contributes into common source file path
-		sourcePathComponents := tspath.GetNormalizedPathComponents(sourceFile, currentDirectory)
-
-		// The base file name is not part of the common directory path
-		sourcePathComponents = sourcePathComponents[:len(sourcePathComponents)-1]
-
-		if commonPathComponents == nil {
-			// first file
-			commonPathComponents = sourcePathComponents
-			continue
-		}
-
-		n := min(len(commonPathComponents), len(sourcePathComponents))
-		for i := range n {
-			if tspath.GetCanonicalFileName(commonPathComponents[i], useCaseSensitiveFileNames) != tspath.GetCanonicalFileName(sourcePathComponents[i], useCaseSensitiveFileNames) {
-				if i == 0 {
-					// Failed to find any common path component
-					return ""
-				}
-
-				// New common path found that is 0 -> i-1
-				commonPathComponents = commonPathComponents[:i]
-				break
-			}
-		}
-
-		// If the sourcePathComponents was shorter than the commonPathComponents, truncate to the sourcePathComponents
-		if len(sourcePathComponents) < len(commonPathComponents) {
-			commonPathComponents = commonPathComponents[:len(sourcePathComponents)]
-		}
-	}
-
-	if len(commonPathComponents) == 0 {
-		// Can happen when all input files are .d.ts files
-		return currentDirectory
-	}
-
-	return tspath.GetPathFromPathComponents(commonPathComponents)
-}
-
-func getCommonSourceDirectory(options *core.CompilerOptions, files []string, currentDirectory string, useCaseSensitiveFileNames bool) string {
-	var commonSourceDirectory string
-	if options.RootDir != "" {
-		// If a rootDir is specified use it as the commonSourceDirectory
-		commonSourceDirectory = options.RootDir
-	} else if options.Composite.IsTrue() && options.ConfigFilePath != "" {
-		// If the rootDir is not specified, but the project is composite, then the common source directory
-		// is the directory of the config file.
-		commonSourceDirectory = tspath.GetDirectoryPath(options.ConfigFilePath)
-	} else {
-		commonSourceDirectory = computeCommonSourceDirectoryOfFilenames(files, currentDirectory, useCaseSensitiveFileNames)
-	}
-
-	if len(commonSourceDirectory) > 0 {
-		// Make sure directory path ends with directory separator so this string can directly
-		// used to replace with "" to get the relative path of the source file and the relative path doesn't
-		// start with / making it rooted path
-		commonSourceDirectory = tspath.EnsureTrailingDirectorySeparator(commonSourceDirectory)
-	}
-
-	return commonSourceDirectory
-}
-
 type EmitOptions struct {
 	TargetSourceFile *ast.SourceFile // Single file to emit. If `nil`, emits all files
 	forceDtsEmit     bool

internal/outputpaths/commonsourcedirectory.go

@@ -0,0 +1,72 @@
+package outputpaths
+
+import (
+	"github.com/microsoft/typescript-go/internal/core"
+	"github.com/microsoft/typescript-go/internal/tspath"
+)
+
+func computeCommonSourceDirectoryOfFilenames(fileNames []string, currentDirectory string, useCaseSensitiveFileNames bool) string {
+	var commonPathComponents []string
+	for _, sourceFile := range fileNames {
+		// Each file contributes into common source file path
+		sourcePathComponents := tspath.GetNormalizedPathComponents(sourceFile, currentDirectory)
+
+		// The base file name is not part of the common directory path
+		sourcePathComponents = sourcePathComponents[:len(sourcePathComponents)-1]
+
+		if commonPathComponents == nil {
+			// first file
+			commonPathComponents = sourcePathComponents
+			continue
+		}
+
+		n := min(len(commonPathComponents), len(sourcePathComponents))
+		for i := range n {
+			if tspath.GetCanonicalFileName(commonPathComponents[i], useCaseSensitiveFileNames) != tspath.GetCanonicalFileName(sourcePathComponents[i], useCaseSensitiveFileNames) {
+				if i == 0 {
+					// Failed to find any common path component
+					return ""
+				}
+
+				// New common path found that is 0 -> i-1
+				commonPathComponents = commonPathComponents[:i]
+				break
+			}
+		}
+
+		// If the sourcePathComponents was shorter than the commonPathComponents, truncate to the sourcePathComponents
+		if len(sourcePathComponents) < len(commonPathComponents) {
+			commonPathComponents = commonPathComponents[:len(sourcePathComponents)]
+		}
+	}
+
+	if len(commonPathComponents) == 0 {
+		// Can happen when all input files are .d.ts files
+		return currentDirectory
+	}
+
+	return tspath.GetPathFromPathComponents(commonPathComponents)
+}
+
+func GetCommonSourceDirectory(options *core.CompilerOptions, files func() []string, currentDirectory string, useCaseSensitiveFileNames bool) string {
+	var commonSourceDirectory string
+	if options.RootDir != "" {
+		// If a rootDir is specified use it as the commonSourceDirectory
+		commonSourceDirectory = options.RootDir
+	} else if options.Composite.IsTrue() && options.ConfigFilePath != "" {
+		// If the rootDir is not specified, but the project is composite, then the common source directory
+		// is the directory of the config file.
+		commonSourceDirectory = tspath.GetDirectoryPath(options.ConfigFilePath)
+	} else {
+		commonSourceDirectory = computeCommonSourceDirectoryOfFilenames(files(), currentDirectory, useCaseSensitiveFileNames)
+	}
+
+	if len(commonSourceDirectory) > 0 {
+		// Make sure directory path ends with directory separator so this string can directly
+		// used to replace with "" to get the relative path of the source file and the relative path doesn't
+		// start with / making it rooted path
+		commonSourceDirectory = tspath.EnsureTrailingDirectorySeparator(commonSourceDirectory)
+	}
+
+	return commonSourceDirectory
+}