summaryrefslogtreecommitdiff
path: root/tools/doc/apilinks.js
blob: 35183912d31870308bd1750ee5879e83f65b3ef8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
'use strict';

// Scan API sources for definitions.
//
// Note the output is produced based on a world class parser, adherence to
// conventions, and a bit of guess work. Examples:
//
//  * We scan for top level module.exports statements, and determine what
//    is exported by looking at the source code only (i.e., we don't do
//    an eval). If exports include `Foo`, it probably is a class, whereas
//    if what is exported is `constants` it probably is prefixed by the
//    basename of the source file (e.g., `zlib`), unless that source file is
//    `buffer.js`, in which case the name is just `buf`.  unless the constant
//    is `kMaxLength`, in which case it is `buffer`.
//
//  * We scan for top level definitions for those exports, handling
//    most common cases (e.g., `X.prototype.foo =`, `X.foo =`,
//    `function X(...) {...}`). Over time, we expect to handle more
//    cases (example: ES2015 class definitions).

const acorn = require('../../deps/acorn');
const fs = require('fs');
const path = require('path');
const child_process = require('child_process');

// Run a command, capturing stdout, ignoring errors.
function execSync(command) {
  try {
    return child_process.execSync(
      command,
      { stdio: ['ignore', null, 'ignore'] }
    ).toString().trim();
  } catch {
    return '';
  }
}

// Determine orign repo and tag (or hash) of the most recent commit.
const local_branch = execSync('git name-rev --name-only HEAD');
const tracking_remote = execSync(`git config branch.${local_branch}.remote`);
const remote_url = execSync(`git config remote.${tracking_remote}.url`);
const repo = (remote_url.match(/(\w+\/\w+)\.git\r?\n?$/) ||
             ['', 'nodejs/node'])[1];

const hash = execSync('git log -1 --pretty=%H') || 'master';
const tag = execSync(`git describe --contains ${hash}`).split('\n')[0] || hash;

// Extract definitions from each file specified.
const definition = {};
process.argv.slice(2).forEach((file) => {
  const basename = path.basename(file, '.js');

  // Parse source.
  const source = fs.readFileSync(file, 'utf8');
  const ast = acorn.parse(source, { ecmaVersion: 10, locations: true });
  const program = ast.body;

  // Build link
  const link = `https://github.com/${repo}/blob/${tag}/` +
    path.relative('.', file).replace(/\\/g, '/');

  // Scan for exports.
  const exported = { constructors: [], identifiers: [] };
  program.forEach((statement) => {
    if (statement.type === 'ExpressionStatement') {
      const expr = statement.expression;
      if (expr.type !== 'AssignmentExpression') return;

      let lhs = expr.left;
      if (expr.left.object.type === 'MemberExpression') lhs = lhs.object;
      if (lhs.type !== 'MemberExpression') return;
      if (lhs.object.name !== 'module') return;
      if (lhs.property.name !== 'exports') return;

      let rhs = expr.right;
      while (rhs.type === 'AssignmentExpression') rhs = rhs.right;

      if (rhs.type === 'NewExpression') {
        exported.constructors.push(rhs.callee.name);
      } else if (rhs.type === 'ObjectExpression') {
        rhs.properties.forEach((property) => {
          if (property.value.type === 'Identifier') {
            exported.identifiers.push(property.value.name);
            if (/^[A-Z]/.test(property.value.name[0])) {
              exported.constructors.push(property.value.name);
            }
          }
        });
      } else if (rhs.type === 'Identifier') {
        exported.identifiers.push(rhs.name);
      }
    } else if (statement.type === 'VariableDeclaration') {
      for (const decl of statement.declarations) {
        let init = decl.init;
        while (init && init.type === 'AssignmentExpression') init = init.left;
        if (!init || init.type !== 'MemberExpression') continue;
        if (init.object.name !== 'module') continue;
        if (init.property.name !== 'exports') continue;
        exported.constructors.push(decl.id.name);
        definition[decl.id.name] = `${link}#L${statement.loc.start.line}`;
      }
    }
  });

  // Scan for definitions matching those exports; currently supports:
  //
  //   ClassName.foo = ...;
  //   ClassName.prototype.foo = ...;
  //   function Identifier(...) {...};
  //
  const indirect = {};

  program.forEach((statement) => {
    if (statement.type === 'ExpressionStatement') {
      const expr = statement.expression;
      if (expr.type !== 'AssignmentExpression') return;
      if (expr.left.type !== 'MemberExpression') return;

      let object;
      if (expr.left.object.type === 'MemberExpression') {
        if (expr.left.object.property.name !== 'prototype') return;
        object = expr.left.object.object;
      } else if (expr.left.object.type === 'Identifier') {
        object = expr.left.object;
      } else {
        return;
      }

      if (!exported.constructors.includes(object.name)) return;

      let objectName = object.name;
      if (expr.left.object.type === 'MemberExpression') {
        objectName = objectName.toLowerCase();
        if (objectName === 'buffer') objectName = 'buf';
      }

      let name = expr.left.property.name;
      if (expr.left.computed) {
        name = `${objectName}[${name}]`;
      } else {
        name = `${objectName}.${name}`;
      }

      definition[name] = `${link}#L${statement.loc.start.line}`;

      if (expr.left.property.name === expr.right.name) {
        indirect[expr.right.name] = name;
      }

    } else if (statement.type === 'FunctionDeclaration') {
      const name = statement.id.name;
      if (!exported.identifiers.includes(name)) return;
      if (basename.startsWith('_')) return;
      definition[`${basename}.${name}`] =
        `${link}#L${statement.loc.start.line}`;
    }
  });

  // Search for indirect references of the form ClassName.foo = foo;
  if (Object.keys(indirect).length > 0) {
    program.forEach((statement) => {
      if (statement.type === 'FunctionDeclaration') {
        const name = statement.id.name;
        if (indirect[name]) {
          definition[indirect[name]] = `${link}#L${statement.loc.start.line}`;
        }
      }
    });
  }
});

console.log(JSON.stringify(definition, null, 2));