1 | # parse-json
|
---|
2 |
|
---|
3 | > Parse JSON with more helpful errors
|
---|
4 |
|
---|
5 | ## Install
|
---|
6 |
|
---|
7 | ```
|
---|
8 | $ npm install parse-json
|
---|
9 | ```
|
---|
10 |
|
---|
11 | ## Usage
|
---|
12 |
|
---|
13 | ```js
|
---|
14 | const parseJson = require('parse-json');
|
---|
15 |
|
---|
16 | const json = '{\n\t"foo": true,\n}';
|
---|
17 |
|
---|
18 |
|
---|
19 | JSON.parse(json);
|
---|
20 | /*
|
---|
21 | undefined:3
|
---|
22 | }
|
---|
23 | ^
|
---|
24 | SyntaxError: Unexpected token }
|
---|
25 | */
|
---|
26 |
|
---|
27 |
|
---|
28 | parseJson(json);
|
---|
29 | /*
|
---|
30 | JSONError: Unexpected token } in JSON at position 16 while parsing near '{ "foo": true,}'
|
---|
31 |
|
---|
32 | 1 | {
|
---|
33 | 2 | "foo": true,
|
---|
34 | > 3 | }
|
---|
35 | | ^
|
---|
36 | */
|
---|
37 |
|
---|
38 |
|
---|
39 | parseJson(json, 'foo.json');
|
---|
40 | /*
|
---|
41 | JSONError: Unexpected token } in JSON at position 16 while parsing near '{ "foo": true,}' in foo.json
|
---|
42 |
|
---|
43 | 1 | {
|
---|
44 | 2 | "foo": true,
|
---|
45 | > 3 | }
|
---|
46 | | ^
|
---|
47 | */
|
---|
48 |
|
---|
49 |
|
---|
50 | // You can also add the filename at a later point
|
---|
51 | try {
|
---|
52 | parseJson(json);
|
---|
53 | } catch (error) {
|
---|
54 | if (error instanceof parseJson.JSONError) {
|
---|
55 | error.fileName = 'foo.json';
|
---|
56 | }
|
---|
57 |
|
---|
58 | throw error;
|
---|
59 | }
|
---|
60 | /*
|
---|
61 | JSONError: Unexpected token } in JSON at position 16 while parsing near '{ "foo": true,}' in foo.json
|
---|
62 |
|
---|
63 | 1 | {
|
---|
64 | 2 | "foo": true,
|
---|
65 | > 3 | }
|
---|
66 | | ^
|
---|
67 | */
|
---|
68 | ```
|
---|
69 |
|
---|
70 | ## API
|
---|
71 |
|
---|
72 | ### parseJson(string, reviver?, filename?)
|
---|
73 |
|
---|
74 | Throws a `JSONError` when there is a parsing error.
|
---|
75 |
|
---|
76 | #### string
|
---|
77 |
|
---|
78 | Type: `string`
|
---|
79 |
|
---|
80 | #### reviver
|
---|
81 |
|
---|
82 | Type: `Function`
|
---|
83 |
|
---|
84 | 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
|
---|
85 | ) for more.
|
---|
86 |
|
---|
87 | #### filename
|
---|
88 |
|
---|
89 | Type: `string`
|
---|
90 |
|
---|
91 | Filename displayed in the error message.
|
---|
92 |
|
---|
93 | ### parseJson.JSONError
|
---|
94 |
|
---|
95 | Exposed for `instanceof` checking.
|
---|
96 |
|
---|
97 | #### fileName
|
---|
98 |
|
---|
99 | Type: `string`
|
---|
100 |
|
---|
101 | The filename displayed in the error message.
|
---|
102 |
|
---|
103 | #### codeFrame
|
---|
104 |
|
---|
105 | Type: `string`
|
---|
106 |
|
---|
107 | The printable section of the JSON which produces the error.
|
---|
108 |
|
---|
109 | ---
|
---|
110 |
|
---|
111 | <div align="center">
|
---|
112 | <b>
|
---|
113 | <a href="https://tidelift.com/subscription/pkg/npm-parse-json?utm_source=npm-parse-json&utm_medium=referral&utm_campaign=readme">Get professional support for this package with a Tidelift subscription</a>
|
---|
114 | </b>
|
---|
115 | <br>
|
---|
116 | <sub>
|
---|
117 | Tidelift helps make open source sustainable for maintainers while giving companies<br>assurances about security, maintenance, and licensing for their dependencies.
|
---|
118 | </sub>
|
---|
119 | </div>
|
---|