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
|
import type { Ast, TemplateNode } from '../../parser/interfaces';
import type { NodeVisitor, TransformOptions, Transformer, VisitorFn } from '../../@types/transformer';
import { walk } from 'estree-walker';
// Transformers
import transformStyles from './styles.js';
import transformDoctype from './doctype.js';
import transformModuleScripts from './module-scripts.js';
import transformCodeBlocks from './prism.js';
interface VisitorCollection {
enter: Map<string, VisitorFn[]>;
leave: Map<string, VisitorFn[]>;
}
/** Add visitors to given collection */
function addVisitor(visitor: NodeVisitor, collection: VisitorCollection, nodeName: string, event: 'enter' | 'leave') {
if (typeof visitor[event] !== 'function') return;
if (!collection[event]) collection[event] = new Map<string, VisitorFn[]>();
const visitors = collection[event].get(nodeName) || [];
visitors.push(visitor[event] as any);
collection[event].set(nodeName, visitors);
}
/** Compile visitor actions from transformer */
function collectVisitors(transformer: Transformer, htmlVisitors: VisitorCollection, cssVisitors: VisitorCollection, finalizers: Array<() => Promise<void>>) {
if (transformer.visitors) {
if (transformer.visitors.html) {
for (const [nodeName, visitor] of Object.entries(transformer.visitors.html)) {
addVisitor(visitor, htmlVisitors, nodeName, 'enter');
addVisitor(visitor, htmlVisitors, nodeName, 'leave');
}
}
if (transformer.visitors.css) {
for (const [nodeName, visitor] of Object.entries(transformer.visitors.css)) {
addVisitor(visitor, cssVisitors, nodeName, 'enter');
addVisitor(visitor, cssVisitors, nodeName, 'leave');
}
}
}
finalizers.push(transformer.finalize);
}
/** Utility for formatting visitors */
function createVisitorCollection() {
return {
enter: new Map<string, VisitorFn[]>(),
leave: new Map<string, VisitorFn[]>(),
};
}
/** Walk AST with collected visitors */
function walkAstWithVisitors(tmpl: TemplateNode, collection: VisitorCollection) {
walk(tmpl, {
enter(node, parent, key, index) {
if (collection.enter.has(node.type)) {
// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
const fns = collection.enter.get(node.type)!;
for (let fn of fns) {
fn.call(this, node, parent, key, index);
}
}
},
leave(node, parent, key, index) {
if (collection.leave.has(node.type)) {
// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
const fns = collection.leave.get(node.type)!;
for (let fn of fns) {
fn.call(this, node, parent, key, index);
}
}
},
});
}
/**
* Transform
* Step 2/3 in Astro SSR.
* Transform is the point at which we mutate the AST before sending off to
* Codegen, and then to Snowpack. In some ways, it‘s a preprocessor.
*/
export async function transform(ast: Ast, opts: TransformOptions) {
const htmlVisitors = createVisitorCollection();
const cssVisitors = createVisitorCollection();
const finalizers: Array<() => Promise<void>> = [];
const optimizers = [transformStyles(opts), transformDoctype(opts), transformModuleScripts(opts), transformCodeBlocks(ast.module)];
for (const optimizer of optimizers) {
collectVisitors(optimizer, htmlVisitors, cssVisitors, finalizers);
}
walkAstWithVisitors(ast.css, cssVisitors);
walkAstWithVisitors(ast.html, htmlVisitors);
// Run all of the finalizer functions in parallel because why not.
await Promise.all(finalizers.map((fn) => fn()));
}
|
