perf(#10923): CSS Modules のクラス名をインライン化する (#10930)

* perf(#10923): unwind css module class name

* perf(#10923): support multiple components

* refactor: clean up

* refactor(#10923): avoid `useCssModule()`

* fix(#10923): allow direct literal class name

* fix(#10923): avoid computed class name

* fix(#10923): allow literal keys

* fix(#10923): typo

* fix(#10923): invalid class names

* chore: test

* revert: test

This reverts commit 5c7ef366eceebe8ba260efa4d5d675f6c1775c45.

* fix(#10923): hidden tale

* perf(#10923): also unwind scoped css contained components

* perf(#10923): `normalizeClass` AOT compilation

---------

Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>

1 files changed, 275 insertions, 0 deletions

diff --git a/packages/frontend/lib/rollup-plugin-unwind-css-module-class-name.ts b/packages/frontend/lib/rollup-plugin-unwind-css-module-class-name.ts
new file mode 100644
index 0000000000..a18f0d9049
--- /dev/null
+++ b/packages/frontend/lib/rollup-plugin-unwind-css-module-class-name.ts
@@ -0,0 +1,275 @@
+import { generate } from 'astring';
+import * as estree from 'estree';
+import { walk } from '../node_modules/estree-walker/src/index.js';
+import type * as estreeWalker from 'estree-walker';
+import type { Plugin } from 'vite';
+
+function isFalsyIdentifier(identifier: estree.Identifier): boolean {
+	return identifier.name === 'undefined' || identifier.name === 'NaN';
+}
+
+function normalizeClassWalker(tree: estree.Node): string | null {
+	if (tree.type === 'Identifier') return isFalsyIdentifier(tree) ? '' : null;
+	if (tree.type === 'Literal') return typeof tree.value === 'string' ? tree.value : '';
+	if (tree.type === 'BinaryExpression') {
+		if (tree.operator !== '+') return null;
+		const left = normalizeClassWalker(tree.left);
+		const right = normalizeClassWalker(tree.right);
+		if (left === null || right === null) return null;
+		return `${left}${right}`;
+	}
+	if (tree.type === 'TemplateLiteral') {
+		if (tree.expressions.some((x) => x.type !== 'Literal' && (x.type !== 'Identifier' || !isFalsyIdentifier(x)))) return null;
+		return tree.quasis.reduce((a, c, i) => {
+			const v = i === tree.quasis.length - 1 ? '' : (tree.expressions[i] as Partial<estree.Literal>).value;
+			return a + c.value.raw + (typeof v === 'string' ? v : '');
+		}, '');
+	}
+	if (tree.type === 'ArrayExpression') {
+		const values = tree.elements.map((treeNode) => {
+			if (treeNode === null) return '';
+			if (treeNode.type === 'SpreadElement') return normalizeClassWalker(treeNode.argument);
+			return normalizeClassWalker(treeNode);
+		});
+		if (values.some((x) => x === null)) return null;
+		return values.join(' ');
+	}
+	if (tree.type === 'ObjectExpression') {
+		const values = tree.properties.map((treeNode) => {
+			if (treeNode.type === 'SpreadElement') return normalizeClassWalker(treeNode.argument);
+			let x = treeNode.value;
+			let inveted = false;
+			while (x.type === 'UnaryExpression' && x.operator === '!') {
+				x = x.argument;
+				inveted = !inveted;
+			}
+			if (x.type === 'Literal') {
+				if (inveted === !x.value) {
+					return treeNode.key.type === 'Identifier' ? treeNode.computed ? null : treeNode.key.name : treeNode.key.type === 'Literal' ? treeNode.key.value : '';
+				} else {
+					return '';
+				}
+			}
+			if (x.type === 'Identifier') {
+				if (inveted !== isFalsyIdentifier(x)) {
+					return '';
+				} else {
+					return null;
+				}
+			}
+			return null;
+		});
+		if (values.some((x) => x === null)) return null;
+		return values.join(' ');
+	}
+	console.error(`Unexpected node type: ${tree.type}`);
+	return null;
+}
+
+export function normalizeClass(tree: estree.Node): string | null {
+	const walked = normalizeClassWalker(tree);
+	return walked && walked.replace(/^\s+|\s+(?=\s)|\s+$/g, '');
+}
+
+export function unwindCssModuleClassName(ast: estree.Node): void {
+	(walk as typeof estreeWalker.walk)(ast, {
+		enter(node, parent): void {
+			if (parent?.type !== 'Program') return;
+			if (node.type !== 'VariableDeclaration') return;
+			if (node.declarations.length !== 1) return;
+			if (node.declarations[0].id.type !== 'Identifier') return;
+			const name = node.declarations[0].id.name;
+			if (node.declarations[0].init?.type !== 'CallExpression') return;
+			if (node.declarations[0].init.callee.type !== 'Identifier') return;
+			if (node.declarations[0].init.callee.name !== '_export_sfc') return;
+			if (node.declarations[0].init.arguments.length !== 2) return;
+			if (node.declarations[0].init.arguments[0].type !== 'Identifier') return;
+			const ident = node.declarations[0].init.arguments[0].name;
+			if (!ident.startsWith('_sfc_main')) return;
+			if (node.declarations[0].init.arguments[1].type !== 'ArrayExpression') return;
+			if (node.declarations[0].init.arguments[1].elements.length === 0) return;
+			const __cssModulesIndex = node.declarations[0].init.arguments[1].elements.findIndex((x) => {
+				if (x?.type !== 'ArrayExpression') return false;
+				if (x.elements.length !== 2) return false;
+				if (x.elements[0]?.type !== 'Literal') return false;
+				if (x.elements[0].value !== '__cssModules') return false;
+				if (x.elements[1]?.type !== 'Identifier') return false;
+				return true;
+			});
+			if (!~__cssModulesIndex) return;
+			const cssModuleForestName = ((node.declarations[0].init.arguments[1].elements[__cssModulesIndex] as estree.ArrayExpression).elements[1] as estree.Identifier).name;
+			const cssModuleForestNode = parent.body.find((x) => {
+				if (x.type !== 'VariableDeclaration') return false;
+				if (x.declarations.length !== 1) return false;
+				if (x.declarations[0].id.type !== 'Identifier') return false;
+				if (x.declarations[0].id.name !== cssModuleForestName) return false;
+				if (x.declarations[0].init?.type !== 'ObjectExpression') return false;
+				return true;
+			}) as unknown as estree.VariableDeclaration;
+			const moduleForest = new Map((cssModuleForestNode.declarations[0].init as estree.ObjectExpression).properties.flatMap((property) => {
+				if (property.type !== 'Property') return [];
+				if (property.key.type !== 'Literal') return [];
+				if (property.value.type !== 'Identifier') return [];
+				return [[property.key.value as string, property.value.name as string]];
+			}));
+			const sfcMain = parent.body.find((x) => {
+				if (x.type !== 'VariableDeclaration') return false;
+				if (x.declarations.length !== 1) return false;
+				if (x.declarations[0].id.type !== 'Identifier') return false;
+				if (x.declarations[0].id.name !== ident) return false;
+				return true;
+			}) as unknown as estree.VariableDeclaration;
+			if (sfcMain.declarations[0].init?.type !== 'CallExpression') return;
+			if (sfcMain.declarations[0].init.callee.type !== 'Identifier') return;
+			if (sfcMain.declarations[0].init.callee.name !== 'defineComponent') return;
+			if (sfcMain.declarations[0].init.arguments.length !== 1) return;
+			if (sfcMain.declarations[0].init.arguments[0].type !== 'ObjectExpression') return;
+			const setup = sfcMain.declarations[0].init.arguments[0].properties.find((x) => {
+				if (x.type !== 'Property') return false;
+				if (x.key.type !== 'Identifier') return false;
+				if (x.key.name !== 'setup') return false;
+				return true;
+			}) as unknown as estree.Property;
+			if (setup.value.type !== 'FunctionExpression') return;
+			const render = setup.value.body.body.find((x) => {
+				if (x.type !== 'ReturnStatement') return false;
+				return true;
+			}) as unknown as estree.ReturnStatement;
+			if (render.argument?.type !== 'ArrowFunctionExpression') return;
+			if (render.argument.params.length !== 2) return;
+			const ctx = render.argument.params[0];
+			if (ctx.type !== 'Identifier') return;
+			if (ctx.name !== '_ctx') return;
+			if (render.argument.body.type !== 'BlockStatement') return;
+			for (const [key, value] of moduleForest) {
+				const cssModuleTreeNode = parent.body.find((x) => {
+					if (x.type !== 'VariableDeclaration') return false;
+					if (x.declarations.length !== 1) return false;
+					if (x.declarations[0].id.type !== 'Identifier') return false;
+					if (x.declarations[0].id.name !== value) return false;
+					return true;
+				}) as unknown as estree.VariableDeclaration;
+				if (cssModuleTreeNode.declarations[0].init?.type !== 'ObjectExpression') return;
+				const moduleTree = new Map(cssModuleTreeNode.declarations[0].init.properties.flatMap((property) => {
+					if (property.type !== 'Property') return [];
+					const actualKey = property.key.type === 'Identifier' ? property.key.name : property.key.type === 'Literal' ? property.key.value : null;
+					if (typeof actualKey !== 'string') return [];
+					if (property.value.type === 'Literal') return [[actualKey, property.value.value as string]];
+					if (property.value.type !== 'Identifier') return [];
+					const labelledValue = property.value.name;
+					const actualValue = parent.body.find((x) => {
+						if (x.type !== 'VariableDeclaration') return false;
+						if (x.declarations.length !== 1) return false;
+						if (x.declarations[0].id.type !== 'Identifier') return false;
+						if (x.declarations[0].id.name !== labelledValue) return false;
+						return true;
+					}) as unknown as estree.VariableDeclaration;
+					if (actualValue.declarations[0].init?.type !== 'Literal') return [];
+					return [[actualKey, actualValue.declarations[0].init.value as string]];
+				}));
+				(walk as typeof estreeWalker.walk)(render.argument.body, {
+					enter(childNode) {
+						if (childNode.type !== 'MemberExpression') return;
+						if (childNode.object.type !== 'MemberExpression') return;
+						if (childNode.object.object.type !== 'Identifier') return;
+						if (childNode.object.object.name !== ctx.name) return;
+						if (childNode.object.property.type !== 'Identifier') return;
+						if (childNode.object.property.name !== key) return;
+						if (childNode.property.type !== 'Identifier') return;
+						const actualValue = moduleTree.get(childNode.property.name);
+						if (actualValue === undefined) return;
+						this.replace({
+							type: 'Literal',
+							value: actualValue,
+						});
+					},
+				});
+				(walk as typeof estreeWalker.walk)(render.argument.body, {
+					enter(childNode) {
+						if (childNode.type !== 'MemberExpression') return;
+						if (childNode.object.type !== 'MemberExpression') return;
+						if (childNode.object.object.type !== 'Identifier') return;
+						if (childNode.object.object.name !== ctx.name) return;
+						if (childNode.object.property.type !== 'Identifier') return;
+						if (childNode.object.property.name !== key) return;
+						if (childNode.property.type !== 'Identifier') return;
+						console.error(`Undefined style detected: ${key}.${childNode.property.name} (in ${name})`);
+						this.replace({
+							type: 'Identifier',
+							name: 'undefined',
+						});
+					},
+				});
+				(walk as typeof estreeWalker.walk)(render.argument.body, {
+					enter(childNode) {
+						if (childNode.type !== 'CallExpression') return;
+						if (childNode.callee.type !== 'Identifier') return;
+						if (childNode.callee.name !== 'normalizeClass') return;
+						if (childNode.arguments.length !== 1) return;
+						const normalized = normalizeClass(childNode.arguments[0]);
+						if (normalized === null) return;
+						this.replace({
+							type: 'Literal',
+							value: normalized,
+						});
+					},
+				});
+			}
+			if (node.declarations[0].init.arguments[1].elements.length === 1) {
+				this.replace({
+					type: 'VariableDeclaration',
+					declarations: [{
+						type: 'VariableDeclarator',
+						id: {
+							type: 'Identifier',
+							name: node.declarations[0].id.name,
+						},
+						init: {
+							type: 'Identifier',
+							name: ident,
+						},
+					}],
+					kind: 'const',
+				});
+			} else {
+				this.replace({
+					type: 'VariableDeclaration',
+					declarations: [{
+						type: 'VariableDeclarator',
+						id: {
+							type: 'Identifier',
+							name: node.declarations[0].id.name,
+						},
+						init: {
+							type: 'CallExpression',
+							callee: {
+								type: 'Identifier',
+								name: '_export_sfc',
+							},
+							arguments: [{
+								type: 'Identifier',
+								name: ident,
+							}, {
+								type: 'ArrayExpression',
+								elements: node.declarations[0].init.arguments[1].elements.slice(0, __cssModulesIndex).concat(node.declarations[0].init.arguments[1].elements.slice(__cssModulesIndex + 1)),
+							}],
+						},
+					}],
+					kind: 'const',
+				});
+			}
+		},
+	});
+}
+
+// eslint-disable-next-line import/no-default-export
+export default function pluginUnwindCssModuleClassName(): Plugin {
+	return {
+		name: 'UnwindCssModuleClassName',
+		renderChunk(code): { code: string } {
+			const ast = this.parse(code) as unknown as estree.Node;
+			unwindCssModuleClassName(ast);
+			return { code: generate(ast) };
+		},
+	};
+}