forked from zhurui/management
143 lines
2.8 KiB
Markdown
143 lines
2.8 KiB
Markdown
# @babel/code-frame
|
|
|
|
> Generate errors that contain a code frame that point to source locations.
|
|
|
|
## Install
|
|
|
|
```sh
|
|
npm install --save-dev @babel/code-frame
|
|
```
|
|
|
|
## Usage
|
|
|
|
```js
|
|
import { codeFrameColumns } from '@babel/code-frame';
|
|
|
|
const rawLines = `class Foo {
|
|
constructor()
|
|
}`;
|
|
const location = { start: { line: 2, column: 16 } };
|
|
|
|
const result = codeFrameColumns(rawLines, location, { /* options */ });
|
|
|
|
console.log(result);
|
|
```
|
|
|
|
```
|
|
1 | class Foo {
|
|
> 2 | constructor()
|
|
| ^
|
|
3 | }
|
|
```
|
|
|
|
If the column number is not known, you may omit it.
|
|
|
|
You can also pass an `end` hash in `location`.
|
|
|
|
```js
|
|
import { codeFrameColumns } from '@babel/code-frame';
|
|
|
|
const rawLines = `class Foo {
|
|
constructor() {
|
|
console.log("hello");
|
|
}
|
|
}`;
|
|
const location = { start: { line: 2, column: 17 }, end: { line: 4, column: 3 } };
|
|
|
|
const result = codeFrameColumns(rawLines, location, { /* options */ });
|
|
|
|
console.log(result);
|
|
```
|
|
|
|
```
|
|
1 | class Foo {
|
|
> 2 | constructor() {
|
|
| ^
|
|
> 3 | console.log("hello");
|
|
| ^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
> 4 | }
|
|
| ^^^
|
|
5 | };
|
|
```
|
|
|
|
## Options
|
|
|
|
### `highlightCode`
|
|
|
|
`boolean`, defaults to `false`.
|
|
|
|
Toggles syntax highlighting the code as JavaScript for terminals.
|
|
|
|
|
|
### `linesAbove`
|
|
|
|
`number`, defaults to `2`.
|
|
|
|
Adjust the number of lines to show above the error.
|
|
|
|
### `linesBelow`
|
|
|
|
`number`, defaults to `3`.
|
|
|
|
Adjust the number of lines to show below the error.
|
|
|
|
### `forceColor`
|
|
|
|
`boolean`, defaults to `false`.
|
|
|
|
Enable this to forcibly syntax highlight the code as JavaScript (for non-terminals); overrides `highlightCode`.
|
|
|
|
### `message`
|
|
|
|
`string`, otherwise nothing
|
|
|
|
Pass in a string to be displayed inline (if possible) next to the highlighted
|
|
location in the code. If it can't be positioned inline, it will be placed above
|
|
the code frame.
|
|
|
|
```
|
|
1 | class Foo {
|
|
> 2 | constructor()
|
|
| ^ Missing {
|
|
3 | };
|
|
```
|
|
|
|
## Upgrading from prior versions
|
|
|
|
Prior to version 7, the only API exposed by this module was for a single line and optional column pointer. The old API will now log a deprecation warning.
|
|
|
|
The new API takes a `location` object, similar to what is available in an AST.
|
|
|
|
This is an example of the deprecated (but still available) API:
|
|
|
|
```js
|
|
import codeFrame from '@babel/code-frame';
|
|
|
|
const rawLines = `class Foo {
|
|
constructor()
|
|
}`;
|
|
const lineNumber = 2;
|
|
const colNumber = 16;
|
|
|
|
const result = codeFrame(rawLines, lineNumber, colNumber, { /* options */ });
|
|
|
|
console.log(result);
|
|
```
|
|
|
|
To get the same highlighting using the new API:
|
|
|
|
```js
|
|
import { codeFrameColumns } from '@babel/code-frame';
|
|
|
|
const rawLines = `class Foo {
|
|
constructor() {
|
|
console.log("hello");
|
|
}
|
|
}`;
|
|
const location = { start: { line: 2, column: 16 } };
|
|
|
|
const result = codeFrameColumns(rawLines, location, { /* options */ });
|
|
|
|
console.log(result);
|
|
```
|