feat: make stripComments optional for syntax detection(#217)

unjs · Jan 11, 2024 · c29618f · c29618f
1 parent 4ffc601
commit c29618f
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Showing 2 changed files with 43 additions and 7 deletions.
diff --git a/src/syntax.ts b/src/syntax.ts
@@ -14,17 +14,35 @@ const COMMENT_RE = /\/\*.+?\*\/|\/\/.*(?=[nr])/g;
 
 const BUILTIN_EXTENSIONS = new Set([".mjs", ".cjs", ".node", ".wasm"]);
 
-export function hasESMSyntax(code: string): boolean {
-  return ESM_RE.test(code.replace(COMMENT_RE, ""));
+export type DetectSyntaxOptions = { stripComments?: boolean };
+
+export function hasESMSyntax(
+  code: string,
+  opts: DetectSyntaxOptions = {},
+): boolean {
+  if (opts.stripComments) {
+    code = code.replace(COMMENT_RE, "");
+  }
+  return ESM_RE.test(code);
 }
 
-export function hasCJSSyntax(code: string): boolean {
-  return CJS_RE.test(code.replace(COMMENT_RE, ""));
+export function hasCJSSyntax(
+  code: string,
+  opts: DetectSyntaxOptions = {},
+): boolean {
+  if (opts.stripComments) {
+    code = code.replace(COMMENT_RE, "");
+  }
+  return CJS_RE.test(code);
 }
 
-export function detectSyntax(code: string) {
-  const hasESM = hasESMSyntax(code);
-  const hasCJS = hasCJSSyntax(code);
+export function detectSyntax(code: string, opts: DetectSyntaxOptions = {}) {
+  if (opts.stripComments) {
+    code = code.replace(COMMENT_RE, "");
+  }
+  // We strip comments once hence not passing opts down to hasESMSyntax and hasCJSSyntax
+  const hasESM = hasESMSyntax(code, {});
+  const hasCJS = hasCJSSyntax(code, {});
 
   return {
     hasESM,

diff --git a/test/syntax.test.ts b/test/syntax.test.ts
@@ -61,6 +61,11 @@ const staticTests = {
     isMixed: false,
   },
   "export class": { hasESM: true, hasCJS: false, isMixed: false },
+  "const start = '/* ';import foo from 'bar';const end = ' */'": {
+    hasESM: true,
+    hasCJS: false,
+    isMixed: false,
+  },
   // CJS
   "exports.c={}": { hasESM: false, hasCJS: true, isMixed: false },
   "const b=true;module.exports={b};": {
@@ -82,6 +87,9 @@ const staticTests = {
     isMixed: false,
   },
   "const a={};": { hasESM: false, hasCJS: false, isMixed: false },
+};
+
+const staticTestsWithComments = {
   '// They\'re exposed using "export import" so that types are passed along as expected\nmodule.exports={};':
     { hasESM: false, hasCJS: true, isMixed: false },
 };
@@ -94,6 +102,16 @@ describe("detectSyntax", () => {
   }
 });
 
+describe("detectSyntax (with comment)", () => {
+  for (const [input, result] of Object.entries(staticTestsWithComments)) {
+    it(input, () => {
+      expect(detectSyntax(input, { stripComments: true })).to.deep.equal(
+        result,
+      );
+    });
+  }
+});
+
 const nodeImportTests = {
   "node:fs": true,
   fs: true,