forked from babel/babel
/
decorators.js
167 lines (145 loc) 路 4.38 KB
/
decorators.js
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
import { types as t, template } from "@babel/core";
import ReplaceSupers from "@babel/helper-replace-supers";
import nameFunction from "@babel/helper-function-name";
export function hasOwnDecorators(node) {
return !!(node.decorators && node.decorators.length);
}
export function hasDecorators(node) {
return hasOwnDecorators(node) || node.body.body.some(hasOwnDecorators);
}
function prop(key, value) {
if (!value) return null;
return t.objectProperty(t.identifier(key), value);
}
function method(key, body) {
return t.objectMethod(
"method",
t.identifier(key),
[],
t.blockStatement(body),
);
}
function takeDecorators(node) {
let result;
if (node.decorators && node.decorators.length > 0) {
result = t.arrayExpression(
node.decorators.map(decorator => decorator.expression),
);
}
node.decorators = undefined;
return result;
}
function getKey(node) {
if (node.computed) {
return node.key;
} else if (t.isIdentifier(node.key)) {
return t.stringLiteral(node.key.name);
} else {
return t.stringLiteral(String(node.key.value));
}
}
// NOTE: This function can be easily bound as .bind(file, classRef, superRef)
// to make it easier to use it in a loop.
function extractElementDescriptor(/* this: File, */ classRef, superRef, path) {
const { node, scope } = path;
const isMethod = path.isClassMethod();
if (path.isPrivate()) {
throw path.buildCodeFrameError(
`Private ${
isMethod ? "methods" : "fields"
} in decorated classes are not supported yet.`,
);
}
new ReplaceSupers(
{
methodPath: path,
methodNode: node,
objectRef: classRef,
isStatic: node.static,
superRef,
scope,
file: this,
},
true,
).replace();
const properties = [
prop("kind", t.stringLiteral(isMethod ? node.kind : "field")),
prop("decorators", takeDecorators(node)),
prop("static", node.static && t.booleanLiteral(true)),
prop("key", getKey(node)),
].filter(Boolean);
if (isMethod) {
const id = node.computed ? null : node.key;
t.toExpression(node);
properties.push(prop("value", nameFunction({ node, id, scope }) || node));
} else if (node.value) {
properties.push(
method("value", template.statements.ast`return ${node.value}`),
);
} else {
properties.push(prop("value", scope.buildUndefinedNode()));
}
path.remove();
return t.objectExpression(properties);
}
function addDecorateHelper(file) {
try {
return file.addHelper("decorate");
} catch (err) {
if (err.code === "BABEL_HELPER_UNKNOWN") {
err.message +=
"\n '@babel/plugin-transform-decorators' in non-legacy mode" +
" requires '@babel/core' version ^7.0.2 and you appear to be using" +
" an older version.";
}
throw err;
}
}
export function buildDecoratedClass(ref, path, elements, file) {
const { node, scope } = path;
const initializeId = scope.generateUidIdentifier("initialize");
const isDeclaration = node.id && path.isDeclaration();
const isStrict = path.isInStrictMode();
const { superClass } = node;
node.type = "ClassDeclaration";
if (!node.id) node.id = t.cloneNode(ref);
let superId;
if (superClass) {
superId = scope.generateUidIdentifierBasedOnNode(node.superClass, "super");
node.superClass = superId;
}
const classDecorators = takeDecorators(node);
const definitions = t.arrayExpression(
elements
// Ignore TypeScript's abstract methods (see #10514)
.filter(element => !element.node.abstract)
.map(extractElementDescriptor.bind(file, node.id, superId)),
);
let replacement = template.expression.ast`
${addDecorateHelper(file)}(
${classDecorators || t.nullLiteral()},
function (${initializeId}, ${superClass ? superId : null}) {
${node}
return { F: ${t.cloneNode(node.id)}, d: ${definitions} };
},
${superClass}
)
`;
let classPathDesc = "arguments.1.body.body.0";
if (!isStrict) {
replacement.arguments[1].body.directives.push(
t.directive(t.directiveLiteral("use strict")),
);
}
if (isDeclaration) {
replacement = template.ast`let ${ref} = ${replacement}`;
classPathDesc = "declarations.0.init." + classPathDesc;
}
return {
instanceNodes: [template.statement.ast`${initializeId}(this)`],
wrapClass(path) {
path.replaceWith(replacement);
return path.get(classPathDesc);
},
};
}