angular/devtools

Angular DevTools

Angular DevTools is a browser DevTools extension for debugging and profiling Angular applications.

Developing Locally

Set up

Follow the instructions below to set up your Angular DevTools development environment. Note that all commands should be executed in the repository root, not devtools/. All file paths are also relative to the repository root.

Debian Linux, MacOS, and Windows via WSL should build successfully. Building natively on Windows without WSL is not supported at the moment.

To set up your development environment, first install the correct version of Node. If you have nvm set up, this can be done with:

nvm install

Second, install pnpm:

npm install -g pnpm

Third, install NPM dependencies:

pnpm install --frozen-lockfile

Now you should be ready to build the DevTools extension.

Dev builds

To run the extension in development mode run:

pnpm devtools:devserver

This would start a development server that you can access on http://localhost:4200. In development, Angular DevTools uses a "development shell." This is different from "chrome shell" in a way, that it runs the user's app in an iframe. DevTools then communicate with the user's app via message passing.

Dev Install

To actually build and install as a real browser extension in dev mode, use:

pnpm devtools:build:chrome:debug

This will build the extension at dist/bin/devtools/projects/shell-browser/src/prodapp. Then go to chrome://extensions, enable developer mode, and click "Load unpacked" to load the extension from that directory.

Whenever you rebuild the extension, make sure to reload the extension in chrome://extensions, right click on the Angular DevTools panel and click "Reload frame", and refresh the page you're inspecting to make sure changes are applied.

Debugging

Depending on which script you want to debug, you can find them in different locations. In debug mode, these should all have sourcemaps loaded and be unminified.

• The main "Angular DevTools" panel UI runs in its own frame and can be found by clicking "Inspect Element" directly on that UI.
  • Note that this inspects all of Chrome DevTools, which loads Angular DevTools in an iframe.
  • The right entry point is under index.html/ienfalfjdbdpebioblfackkekamfmbnh/...
• Scripts directly executed in the inspected page content's can be found in the normal Sources panel under "Angular DevTools".
  • backend_bundle.js
  • detect_angular_bundle.js
• Content scripts are executed in the inspected page, but within an isolated environment and found in the normal Sources panel, but under the "Content Scripts" section (as opposed to "Page", "Workspace", "Overrides", etc., you may need to click an arrow to expand the list of sections).
  • content_script_bundle.js
  • ng_validate_bundle.js
• The background service worker is found at chrome://extensions.
  • Click on the "Angular DevTools" extension and the "Inspect Views > service worker" button to open a debugger.

Enabling sourcemaps

To enable sourcemaps you need to add the sourcemap = "inline" flag to the esbuild macro located in tools/defaults.bzl.

Running End-to-End Tests

Before running end-to-end tests, you need to start the development server using:

pnpm devtools:devserver

You have two options for running cypress, you can use the interactive cypress UI or you can run Cypress in headless mode.

To open Cypress for Angular DevTools in interactive mode, run:

pnpm devtools:e2e:open

To run Cypress tests headless, use:

pnpm devtools:test:e2e

Release builds

You can build the release version of Angular DevTools for either Chrome or Firefox with:

pnpm devtools:build:chrome:release
pnpm devtools:build:firefox:release

Either way, the built extension will be at dist/bin/devtools/projects/shell-browser/src/prodapp.

Installation

For Chrome, you can install the extension from dist/bin/devtools/projects/shell-browser/src/prodapp by following the guide from here.

For Firefox, to load the extension, you can go to the about:debugging page, click the "This Firefox" option and then click the Load Temporary Add-on button. You'll have to select the manifest file in dist/bin/devtools/projects/shell-browser/src/prodapp directly.