From c717fce42495a93e366a482b0458f930c25dfb61 Mon Sep 17 00:00:00 2001
From: Filipe Silva <filipematossilva@gmail.com>
Date: Thu, 4 May 2017 19:30:32 +0100
Subject: [PATCH] feat(@angular/cli): add flag to not delete output path

Fix #5925
Fix #6193
---
 packages/@angular/cli/commands/build.ts       |  7 +++++++
 packages/@angular/cli/models/build-options.ts |  2 +-
 packages/@angular/cli/tasks/build.ts          |  4 +++-
 packages/@angular/cli/tasks/serve.ts          |  4 +++-
 tests/e2e/tests/build/delete-output-path.ts   | 21 +++++++++++++++++++
 tests/e2e/tests/build/fail-build.ts           | 11 ----------
 6 files changed, 35 insertions(+), 14 deletions(-)
 create mode 100644 tests/e2e/tests/build/delete-output-path.ts
 delete mode 100644 tests/e2e/tests/build/fail-build.ts

diff --git a/packages/@angular/cli/commands/build.ts b/packages/@angular/cli/commands/build.ts
index b1263e704435..e7b1bf4febb6 100644
--- a/packages/@angular/cli/commands/build.ts
+++ b/packages/@angular/cli/commands/build.ts
@@ -118,6 +118,13 @@ export const baseBuildCommandOptions: any = [
     type: String,
     aliases: ['a'],
     description: 'Specifies app name or index to use.'
+  },
+  {
+    name: 'delete-output-path',
+    type: Boolean,
+    default: true,
+    aliases: ['dop'],
+    description: 'Delete output path before build.'
   }
 ];
 
diff --git a/packages/@angular/cli/models/build-options.ts b/packages/@angular/cli/models/build-options.ts
index bed860355c94..74fad4cf6eb4 100644
--- a/packages/@angular/cli/models/build-options.ts
+++ b/packages/@angular/cli/models/build-options.ts
@@ -17,5 +17,5 @@ export interface BuildOptions {
   outputHashing?: string;
   poll?: number;
   app?: string;
-
+  deleteOutputPath?: boolean;
 }
diff --git a/packages/@angular/cli/tasks/build.ts b/packages/@angular/cli/tasks/build.ts
index cdbc1f6cbd18..c984679c5c09 100644
--- a/packages/@angular/cli/tasks/build.ts
+++ b/packages/@angular/cli/tasks/build.ts
@@ -27,7 +27,9 @@ export default Task.extend({
     if (config.project && config.project.ejected) {
       throw new SilentError('An ejected project cannot use the build command anymore.');
     }
-    rimraf.sync(path.resolve(project.root, outputPath));
+    if (runTaskOptions.deleteOutputPath) {
+      rimraf.sync(path.resolve(project.root, outputPath));
+    }
 
     const webpackConfig = new NgCliWebpackConfig(runTaskOptions, app).buildConfig();
     const webpackCompiler = webpack(webpackConfig);
diff --git a/packages/@angular/cli/tasks/serve.ts b/packages/@angular/cli/tasks/serve.ts
index a7d1c7bdacac..7804d1549cc3 100644
--- a/packages/@angular/cli/tasks/serve.ts
+++ b/packages/@angular/cli/tasks/serve.ts
@@ -31,7 +31,9 @@ export default Task.extend({
     if (projectConfig.project && projectConfig.project.ejected) {
       throw new SilentError('An ejected project cannot use the build command anymore.');
     }
-    rimraf.sync(path.resolve(this.project.root, outputPath));
+    if (serveTaskOptions.deleteOutputPath) {
+      rimraf.sync(path.resolve(this.project.root, outputPath));
+    }
 
     const serveDefaults = {
       // default deployUrl to '' on serve to prevent the default from .angular-cli.json
diff --git a/tests/e2e/tests/build/delete-output-path.ts b/tests/e2e/tests/build/delete-output-path.ts
new file mode 100644
index 000000000000..9a5b658f8e7e
--- /dev/null
+++ b/tests/e2e/tests/build/delete-output-path.ts
@@ -0,0 +1,21 @@
+import {ng} from '../../utils/process';
+import {expectToFail} from '../../utils/utils';
+import {deleteFile, expectFileToExist} from '../../utils/fs';
+import {getGlobalVariable} from '../../utils/env';
+
+export default function() {
+  // Skip this in ejected tests.
+  if (getGlobalVariable('argv').eject) {
+    return Promise.resolve();
+  }
+
+  return ng('build')
+    // This is supposed to fail since there's a missing file
+    .then(() => deleteFile('src/app/app.component.ts'))
+    // The build fails but we don't delete the output of the previous build.
+    .then(() => expectToFail(() => ng('build', '--no-delete-output-path')))
+    .then(() => expectFileToExist('dist'))
+    // By default, output path is always cleared.
+    .then(() => expectToFail(() => ng('build')))
+    .then(() => expectToFail(() => expectFileToExist('dist')));
+}
diff --git a/tests/e2e/tests/build/fail-build.ts b/tests/e2e/tests/build/fail-build.ts
deleted file mode 100644
index 4dd01b1e7eb4..000000000000
--- a/tests/e2e/tests/build/fail-build.ts
+++ /dev/null
@@ -1,11 +0,0 @@
-import {ng} from '../../utils/process';
-import {expectToFail} from '../../utils/utils';
-import {deleteFile, expectFileToExist} from '../../utils/fs';
-
-export default function() {
-  return deleteFile('src/app/app.component.ts')
-    // This is supposed to fail since there's a missing file
-    .then(() => expectToFail(() => ng('build')))
-    // Failed builds don't leave behind dist/
-    .then(() => expectToFail(() => expectFileToExist('dist/')));
-}