title: Single-step Debugging Configuration

With the cross-platform code single-step debugging capability provided by VSCode, we can greatly improve the speed of application development based on the Taro development framework, and focus on reducing the complexity of configuration for Windows platform as more mature tools are already available for other platforms.

一、Development Environment Setup

First, prepare the basic development environment for Taro on Windows, as follows (existing development environments can be skipped).

1. Install Node.js

It is recommended to install 10.15 or above, download Node.js

2. Install VSCode

After installing the latest VSCode, it is recommended to install the following plugins:

  • ESlint - Code Specification
  • TSlint - syntax checking

3. Taro Source Code Download

Download: Taro, Default is 2.x branch, if you want to debug Taro Next, please switch to next branch first.

4. Global installation of Node-sass, Lerna and Rollup

  1. npm i -g node-sass --sass_binary_site=https://npm.taobao.org/mirrors/node_sass/
  2. yarn global add lerna
  3. yarn global add rollup

It is recommended to install Node-sass in advance to circumvent any possible abnormal errors.

5. Source code Dependency Installation

1.Use VSCode to open the Taro source directory, and execute yarn in the root directory to install the dependencies required for the project (the first installation will take a long time, please be patient)

2.After yarn finishes executing, run yarn run bootstrap to install dependencies for the subpackages

3.Run yarn build to compile all modules

二、CLI Debugging

1. Configure VSCode Debugging Parameters

Open the .vscode folder in the root of the Taro source code in VSCode and edit launch.json.

The launch.json has the following preset configuration.

```json title=”launch.json” { // … “configurations”: [ //… { “type”: “node”, “request”: “launch”, “name”: “CLI debug”, “program”: “${workspaceFolder}/packages/taro-cli/bin/taro”, // “cwd”: “${project absolute path}”, // “args”: [ // “build”, // “—type”, // “weapp”, // “—watch” // ], “skipFiles”: [ “/**” ] } ] }

  2. Modification steps:
  4. 1. modify **cwd** option to be the target working directory to be debugged
  5. 2. modify args to be the parameter of the command to be debugged
  7. > The detailed configuration of launch.json can be found in [VSCode Documentation](https://code.visualstudio.com/docs/editor/debugging#_launch-configurations)
  9. Example：
  11. ##### taro-build Debugging
  13. Suppose you need to debug the `taro build --weapp --watch` command for the test project.
  15. You can configure launch.json like this.
  17. ```json title="launch.json"
  18. {
  19.   // ...
  20.   "configurations": [
  21.     //...
  22.     {
  23.       // ...
  24.       "cwd": "/Users/User/Desktop/test",
  25.       "args": [
  26.         "build",
  27.         "--type",
  28.         "weapp",
  29.         "--watch"
  30.       ]
  31.     }
  32.   ]
  33. }
taro-init Debugging

Suppose you need to debug the taro init projectName command for the test project.

You can configure launch.json like this:

json title="launch.json" { // ... "configurations": [ //... { // ... "cwd": "/Users/User/Desktop", "args": [ "init", "projectName" ] } ] }

2. Compiling Subpackages

When debugging a subpackage, if you want to debug the modified code, go to the root of the corresponding subpackage and turn on watch mode compilation.

For example, to debug @tarojs/mini-runner, first go to packages/mini-runner/, and then run npm run dev in this directory (the compile command may vary by subpackage, see the package.json of each subpackage for details). This will allow us to debug the code after each change.

3.Links to unpublished libraries

If the currently developed subpackage depends on other subpackages, you can link the other subpackages to use them. The yarn run bootstrap command introduced in Development Environment Setup already creates soft connections for all subpackages.

If you need to add other subpackages as dependencies for the current subpackage, you can execute lerna add [package] --scope=[target] [--dev] in the Taro source root, after which lerna will automatically create the soft chain.

example： @tarojs/cli add @tarojs/webpack-runner as devdependencies：

lerna add @tarojs/webpack-runner --scope=@tarojs/cli --dev

Alternatively, if the softlink fails (e.g. yarn add is executed in a subpackage), you can use the lerna link command to softlink again.

4.Start up debugging

You can start single-step debugging by following the diagram below, please refer to VSCode documentation for detailed debugging operation.

一、Development Environment Setup - 图1

Currently, subpackages of the Taro project are generally compiled with source-map, so it is usually possible to use breakpoints directly in the source code location. If some packages are not compiled with source-map enabled, you can enable it manually and submit Pull Requests.