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# parse-json
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> Parse JSON with more helpful errors
## Install
```
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$ npm install parse-json
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```
## Usage
```js
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const parseJson = require('parse-json');
const json = '{\n\t"foo": true,\n}';
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JSON.parse(json);
/*
undefined:3
}
^
SyntaxError: Unexpected token }
*/
parseJson(json);
/*
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JSONError: Unexpected token } in JSON at position 16 while parsing near '{ "foo": true,}'
1 | {
2 | "foo": true,
> 3 | }
| ^
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*/
parseJson(json, 'foo.json');
/*
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JSONError: Unexpected token } in JSON at position 16 while parsing near '{ "foo": true,}' in foo.json
1 | {
2 | "foo": true,
> 3 | }
| ^
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*/
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// You can also add the filename at a later point
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try {
parseJson(json);
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} catch (error) {
if (error instanceof parseJson.JSONError) {
error.fileName = 'foo.json';
}
throw error;
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}
/*
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JSONError: Unexpected token } in JSON at position 16 while parsing near '{ "foo": true,}' in foo.json
1 | {
2 | "foo": true,
> 3 | }
| ^
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*/
```
## API
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### parseJson(string, reviver?, filename?)
Throws a `JSONError` when there is a parsing error.
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#### string
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Type: `string`
#### reviver
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Type: `Function`
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Prescribes how the value originally produced by parsing is transformed, before being returned. See [`JSON.parse` docs](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse#Using_the_reviver_parameter
) for more.
#### filename
Type: `string`
Filename displayed in the error message.
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### parseJson.JSONError
Exposed for `instanceof` checking.
#### fileName
Type: `string`
The filename displayed in the error message.
#### codeFrame
Type: `string`
The printable section of the JSON which produces the error.
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---
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