67 lines
1.9 KiB
Markdown
67 lines
1.9 KiB
Markdown
# is-expression
|
|
|
|
Validates a string as a JavaScript expression
|
|
|
|
[](https://travis-ci.org/pugjs/is-expression)
|
|
[](https://david-dm.org/pugjs/is-expression)
|
|
[](https://rollingversions.com/pugjs/is-expression)
|
|
[](https://www.npmjs.org/package/is-expression)
|
|
|
|
## Installation
|
|
|
|
npm install is-expression
|
|
|
|
## Usage
|
|
|
|
### `isExpression(src[, options])`
|
|
|
|
Validates a string as a JavaScript expression.
|
|
|
|
`src` contains the source.
|
|
|
|
`options` can contain any Acorn options (since we use Acorn under-the-hood),
|
|
or any of the following:
|
|
|
|
- `throw`: Throw an error if the string is not an expression. The error can
|
|
be an Acorn error, with location information in `err.loc` and `err.pos`.
|
|
Defaults to `false`.
|
|
- `strict`: Use strict mode when trying to parse the string. Defaults to
|
|
`false`. Even if this option is `false`, if you have provided
|
|
`options.sourceType === 'module'` which imples strict mode under ES2015,
|
|
strict mode will be used.
|
|
- `lineComment`: When `true`, allows line comments in the expression.
|
|
Defaults to `false` for safety.
|
|
|
|
See the examples below for usage.
|
|
|
|
## Examples
|
|
|
|
```js
|
|
var isExpression = require('is-expression')
|
|
|
|
isExpression('myVar')
|
|
//=> true
|
|
isExpression('var')
|
|
//=> false
|
|
isExpression('["an", "array", "\'s"].indexOf("index")')
|
|
//=> true
|
|
|
|
isExpression('var', {throw: true})
|
|
// SyntaxError: Unexpected token (1:0)
|
|
// at Parser.pp.raise (acorn/dist/acorn.js:940:13)
|
|
// at ...
|
|
|
|
isExpression('public')
|
|
//=> true
|
|
isExpression('public', {strict: true})
|
|
//=> false
|
|
|
|
isExpression('abc // my comment')
|
|
//=> false
|
|
isExpression('abc // my comment', {lineComment: true})
|
|
//=> true
|
|
```
|
|
|
|
## License
|
|
|
|
MIT
|