diff options
| author | ruki <waruqi@gmail.com> | 2018-11-08 00:43:05 +0800 |
|---|---|---|
| committer | ruki <waruqi@gmail.com> | 2018-11-07 22:18:30 +0800 |
| commit | 89e95b3f143682ed9a006991bacf45c9dcba4818 (patch) | |
| tree | 4f44cf41b828577d583890bdd5a1c31e8491a6ba /node_modules/@babel/plugin-transform-block-scoping/README.md | |
| parent | aa7f0199255277949790b41c56e8ec97dd4f0da4 (diff) | |
| download | xmake-docs-vuepress.tar.gz xmake-docs-vuepress.zip | |
remove node_modulesvuepress
Diffstat (limited to 'node_modules/@babel/plugin-transform-block-scoping/README.md')
| -rw-r--r-- | node_modules/@babel/plugin-transform-block-scoping/README.md | 103 |
1 files changed, 0 insertions, 103 deletions
diff --git a/node_modules/@babel/plugin-transform-block-scoping/README.md b/node_modules/@babel/plugin-transform-block-scoping/README.md deleted file mode 100644 index 7c174e50..00000000 --- a/node_modules/@babel/plugin-transform-block-scoping/README.md +++ /dev/null @@ -1,103 +0,0 @@ -# @babel/plugin-transform-block-scoping - -> Compile ES2015 block scoping (const and let) to ES5 - -## Examples - -**In** - -```javascript -{ - let a = 3 -} - -let a = 3 -``` - -**Out** - -```javascript -{ - var _a = 3; -} - -var a = 3; -``` - -## Constant checks - -This plugin also validates all `const` variables. -Reassignment of constants is a runtime error and it will insert the necessary error code for those. - -## Installation - -```sh -npm install --save-dev @babel/plugin-transform-block-scoping -``` - -## Usage - -### Via `.babelrc` (Recommended) - -**.babelrc** - -Without options: - -```json -{ - "plugins": ["@babel/plugin-transform-block-scoping"] -} -``` - -With options: - -```json -{ - "plugins": [ - ["@babel/plugin-transform-block-scoping", { - "throwIfClosureRequired": true - }] - ] -} -``` - -### Via CLI - -```sh -babel --plugins @babel/plugin-transform-block-scoping script.js -``` - -### Via Node API - -```javascript -require("@babel/core").transform("code", { - plugins: ["@babel/plugin-transform-block-scoping"] -}); -``` - -## Options - -### `throwIfClosureRequired` -`boolean`, defaults to `false`. - -In cases such as the following it's impossible to rewrite let/const without adding an additional function and closure while transforming: - -```javascript -for (let i = 0; i < 5; i++) { - setTimeout(() => console.log(i), 1); -} -``` - -In extremely performance-sensitive code, this can be undesirable. If `"throwIfClosureRequired": true` is set, Babel throws when transforming these patterns instead of automatically adding an additional function. - -### `tdz` -`boolean`, defaults to `false`. - -By default this plugin will ignore the *temporal dead zone (TDZ)* for block-scoped variables. The following code will **not throw an error when transpiled with Babel, which is not spec compliant**: - -```javascript -i -let i; -``` - -If you need these errors you can tell Babel to try and find them by setting `"tdz": true` for this plugin. However, the current implementation might not get all edge cases right and its best to just avoid code like this in the first place. |
