fix(roc-plugin-repo): Fix Jest resolver when using moduleNameMapper

extensions/roc-plugin-repo/src/commands/utils/jest/roc-resolver.js

@@ -1,6 +1,7 @@
-// This version of Roc might not be the same version as is used in the project to launch the CLI
+import fs from 'fs';
 import resolveFrom from 'resolve-from';
 
+// This version of Roc might not be the same version as is used in the project to launch the CLI
 require('roc').runCli({
   invoke: false,
   argv: JSON.parse(process.env.ROC_INITAL_ARGV),
@@ -14,6 +15,24 @@ const jestDefaultResolver = require(resolveFrom(
 )).default;
 const callsites = require('callsites');
 
+// This finds the line number for an error that Jest throws when there is a problem
+// with moduleNameMapper resolving. We use this to find a reference for when we should
+// short-circuit the resolver since it is called in two places for  _resolveStubModuleName
+const lineNumberForModuleMapperError =
+  fs
+    .readFileSync(
+      resolveFrom(require.resolve('jest'), 'jest-resolve/build/index.js'),
+      'utf8',
+    )
+    .split('\n')
+    .findIndex(row => /Could not locate module/.test(row)) + 1;
+
+if (lineNumberForModuleMapperError === 0) {
+  throw new Error(
+    'The integration between Jest and roc-plugin-repo is out of date, please update roc-plugin-repo.',
+  );
+}
+
 module.exports = function customJestResolver(path, options) {
   // This logic manages a bug in Jest that makes mocking fail and should be removed
   // as soon as this problem is addressed. What we are doing here is that we disable
@@ -27,7 +46,11 @@ module.exports = function customJestResolver(path, options) {
   // don't want but adding detection on line number is too fragile.
   //
   // https://github.com/facebook/jest/issues/4985
-  if (callsites()[2].getMethodName() === '_resolveStubModuleName') {
+  const cs = callsites()[2];
+  if (
+    cs.getMethodName() === '_resolveStubModuleName' &&
+    cs.getLineNumber() > lineNumberForModuleMapperError
+  ) {
     return null;
   }
   // return jestDefaultResolver(path, options);