diff --git a/Tasks/JavaToolInstallerV0/javatoolinstaller.ts b/Tasks/JavaToolInstallerV0/javatoolinstaller.ts
index f226f52e4b0b..8c8ed14614b8 100644
--- a/Tasks/JavaToolInstallerV0/javatoolinstaller.ts
+++ b/Tasks/JavaToolInstallerV0/javatoolinstaller.ts
@@ -86,8 +86,10 @@ async function getJava(versionSpec: string) {
 }
 
 /**
- * Return file ending if it is supported. Otherwise throw an error.
+ * Get file ending if it is supported. Otherwise throw an error.
+ * Find file ending, not extension. For example, there is supported .tar.gz file ending but the extension is .gz.
  * @param file Path to a file.
+ * @returns string
  */
 function getSupportedFileEnding(file: string): string {
     const fileEnding: string = supportedFileEndings.find(ending => file.endsWith(ending)); 
@@ -104,6 +106,7 @@ function getSupportedFileEnding(file: string): string {
  * @param sourceFile Path to JDK file.
  * @param fileExtension JDK file extension.
  * @param archiveExtractLocation Path to folder to extract a JDK.
+ * @returns string
  */
 async function installJDK(sourceFile: string, fileExtension: string, archiveExtractLocation: string, extendedJavaHome: string, versionSpec: string): Promise<string> {
     let jdkDirectory;
@@ -140,6 +143,7 @@ async function installJDK(sourceFile: string, fileExtension: string, archiveExtr
  * Get the path to a folder inside the VOLUMES_FOLDER.
  * Only for macOS.
  * @param volumes VOLUMES_FOLDER contents before attaching a disk image.
+ * @returns string
  */
 function getVolumePath(volumes: Set<string>): string {
     const newVolumes: string[] = fs.readdirSync(VOLUMES_FOLDER).filter(volume => !volumes.has(volume));
@@ -154,6 +158,7 @@ function getVolumePath(volumes: Set<string>): string {
  * Get path to a .pkg file.
  * Only for macOS.
  * @param volumePath Path to the folder containing a .pkg file.
+ * @returns string
  */
 function getPackagePath(volumePath: string): string {
     const packages: string[] = fs.readdirSync(volumePath).filter(file => file.endsWith('.pkg'));
@@ -202,12 +207,14 @@ async function installPkg(pkgPath: string, extendedJavaHome: string, versionSpec
 /**
  * Install a .pkg file.
  * Only for macOS.
+ * Returns promise with return code.
  * @param pkgPath Path to a .pkg file.
+ * @returns number
  */
-async function runPkgInstaller(pkgPath: string): Promise<void> {
+async function runPkgInstaller(pkgPath: string): Promise<number> {
     const installer = sudo('installer');
     installer.line(`-package "${pkgPath}" -target /`);
-    await installer.exec();
+    return await installer.exec();
 }
 
 run();
diff --git a/Tasks/JavaToolInstallerV0/taskutils.ts b/Tasks/JavaToolInstallerV0/taskutils.ts
index 084aa02b9e73..c767b478b22b 100644
--- a/Tasks/JavaToolInstallerV0/taskutils.ts
+++ b/Tasks/JavaToolInstallerV0/taskutils.ts
@@ -14,6 +14,7 @@ export function sleepFor(sleepDurationInMilliSeconds: number): Promise<any> {
  * Build a path to file in local root.
  * @param localPathRoot Path to the folder where file should be located.
  * @param fileNameAndPath Path to the file which name should be taken.
+ * @returns string
  */
 export function buildFilePath(localPathRoot: string, fileNameAndPath: string): string {
     const fileName = fileNameAndPath.split(/[\\\/]/).pop();
@@ -25,6 +26,7 @@ export function buildFilePath(localPathRoot: string, fileNameAndPath: string): s
 /**
  * Run a tool with `sudo` on Linux and macOS.
  * Precondition: `toolName` executable is in PATH.
+ * @returns ToolRunner
  */
 export function sudo(toolName: string): ToolRunner {
     if (os.platform() === 'win32') {
@@ -38,22 +40,26 @@ export function sudo(toolName: string): ToolRunner {
 /**
  * Attach a disk image.
  * Only for macOS.
+ * Returns promise with return code.
  * @param sourceFile Path to a disk image file.
+ * @returns number
  */
-export async function attach(sourceFile: string): Promise<void> {
+export async function attach(sourceFile: string): Promise<number> {
     console.log(tl.loc('AttachDiskImage'));
     const hdiutil = sudo('hdiutil');
     hdiutil.line(`attach "${sourceFile}"`);
-    await hdiutil.exec();
+    return await hdiutil.exec();
 }
 
 /**
  * Detach a disk image.
+ * Returns promise with return code.
  * @param volumePath Path to the attached disk image.
+ * @returns number
  */
-export async function detach(volumePath: string): Promise<void> {
+export async function detach(volumePath: string): Promise<number> {
     console.log(tl.loc('DetachDiskImage'));
     const hdiutil = sudo('hdiutil');
     hdiutil.line(`detach "${volumePath}"`);
-    await hdiutil.exec();
+    return await hdiutil.exec();
 }
\ No newline at end of file