Fix empty exports for CommonJS modules imported after quibble()

CHANGELOG.md

@@ -1,3 +1,12 @@
+# Unreleased
+
+* Fix CommonJS modules loaded with `import()` having empty exports after
+  `quibble()` was called from the importing file (Node 20.6–24.17 and 25.x)
+  [#111](https://github.com/testdouble/quibble/issues/111). As a side effect,
+  if a file that called `quibble()` is part of a circular `require()`, it now
+  gets the partially loaded module, as it would without quibble, instead of
+  a second copy
+
 # 0.12.1
 
 * Fix mocking an ES module with a named export whose name isn't an identifier

lib/quibble.js

@@ -192,6 +192,11 @@ const requireWasCalledFromAFileThatHasQuibbledStuff = function () {
 const doWithoutCache = function (request, parent, thingToDo) {
   const filename = Module._resolveFilename(request, parent)
   if (Object.prototype.hasOwnProperty.call(Module._cache, filename)) {
+    if (Module._cache[filename]?.loaded === false) {
+      // Node's ESM loader caches a CommonJS module before loading it, then
+      // reads the exports off that cache entry, so load it where it is
+      return thingToDo()
+    }
     return doAndRestoreCache(filename, thingToDo)
   } else {
     return doAndDeleteCache(filename, thingToDo)

test/esm-fixtures/a-cjs-dependency.cjs

@@ -0,0 +1 @@
+module.exports = 'the real dependency'

test/esm-fixtures/a-cjs-module-with-a-dependency.cjs

@@ -0,0 +1,3 @@
+// Only ever imported by the test that quibbles its dependency, so that
+// import() is what first loads it
+module.exports = { dependency: require('./a-cjs-dependency.cjs') }

test/esm-lib/quibble-esm.test.mjs

@@ -56,6 +56,14 @@ export default {
       assert.equal(result[name], 'replacement')
     }
   },
+  'import() a CommonJS module that requires a quibbled module': async function () {
+    // Node's ESM loader caches a not-yet-loaded CommonJS module before
+    // requiring it, then reads the exports off that same cache entry
+    quibble('../esm-fixtures/a-cjs-dependency.cjs', 'a fake dependency')
+
+    const { default: result } = await import('../esm-fixtures/a-cjs-module-with-a-dependency.cjs')
+    assert.equal(result.dependency, 'a fake dependency')
+  },
   'mock a module after it is used unmocked': async function () {
     const result1 = await import('../esm-fixtures/a-module.mjs')
     assert.deepEqual({ ...result1 }, {