feat: transform string literal in template expression (#191)

Author: Le0Developer

packages/webcrack/src/unminify/test/string-literal-in-template-literal.test.ts

@@ -0,0 +1,25 @@
+import { test } from 'vitest';
+import { testTransform } from '../../../test';
+import stringLiteralInTemplate from '../transforms/string-literal-in-template';
+
+const expectJS = testTransform(stringLiteralInTemplate);
+
+test('string-literal-in-template-literal', () => {
+  expectJS(
+    `
+    const a = \`Hello \${'World'}!\`;
+  `,
+  ).toMatchInlineSnapshot(`const a = \`Hello World!\`;`);
+
+  expectJS(
+    `
+    const a = \`Hello \${'World'}\${'!'}\`;
+  `,
+  ).toMatchInlineSnapshot(`const a = \`Hello World!\`;`);
+
+  expectJS(
+    `
+    const a = \`\${"Hi!"}\`;
+  `,
+  ).toMatchInlineSnapshot(`const a = \`Hi!\`;`);
+});

packages/webcrack/src/unminify/transforms/index.ts

@@ -13,6 +13,7 @@ export { default as removeDoubleNot } from './remove-double-not';
 export { default as sequence } from './sequence';
 export { default as splitForLoopVars } from './split-for-loop-vars';
 export { default as splitVariableDeclarations } from './split-variable-declarations';
+export { default as stringLiteralInTemplate } from './string-literal-in-template';
 export { default as ternaryToIf } from './ternary-to-if';
 export { default as truncateNumberLiteral } from './truncate-number-literal';
 export { default as typeofUndefined } from './typeof-undefined';

packages/webcrack/src/unminify/transforms/string-literal-in-template.ts

@@ -0,0 +1,30 @@
+import * as t from '@babel/types';
+import type { Transform } from '../../ast-utils';
+
+export default {
+  name: 'string-literal-in-template-literal',
+  tags: ['safe'],
+  visitor: () => ({
+    TemplateLiteral(path) {
+      // inline string literals in template literals
+      // e.g. `Hello ${'World'}!` -> `Hello World!`
+      for (let i = 0; i < path.node.expressions.length; i++) {
+        const expr = path.node.expressions[i];
+        if (t.isStringLiteral(expr)) {
+          path.node.expressions.splice(i, 1);
+          const main = path.node.quasis[i];
+          main.value.raw += expr.value;
+
+          const next = path.node.quasis[i + 1];
+          if (next) {
+            main.value.raw += next.value.raw;
+            path.node.quasis.splice(i + 1, 1);
+          }
+
+          this.changes++;
+          i--;
+        }
+      }
+    },
+  }),
+} satisfies Transform;