[jest/cli] stop iterating up at the repo_root and error if no config found (#126853)

packages/kbn-test/src/jest/run.ts

@@ -22,6 +22,7 @@ import { existsSync } from 'fs';
 import { run } from 'jest';
 import { buildArgv } from 'jest-cli/build/cli';
 import { ToolingLog, getTimeReporter } from '@kbn/dev-utils';
+import { REPO_ROOT } from '@kbn/utils';
 import { map } from 'lodash';
 
 // yarn test:jest src/core/server/saved_objects
@@ -67,23 +68,47 @@ export function runJest(configName = 'jest.config.js') {
     log.verbose('commonTestFiles:', commonTestFiles);
 
     let configPath;
-    let devConfigPath;
 
     // sets the working directory to the cwd or the common
     // base directory of the provided test files
     let wd = testFilesProvided ? commonTestFiles : cwd;
+    while (true) {
+      const dev = resolve(wd, devConfigName);
+      if (existsSync(dev)) {
+        configPath = dev;
+        break;
+      }
 
-    devConfigPath = resolve(wd, devConfigName);
-    configPath = resolve(wd, configName);
+      const actual = resolve(wd, configName);
+      if (existsSync(actual)) {
+        configPath = actual;
+        break;
+      }
 
-    while (!existsSync(configPath) && !existsSync(devConfigPath)) {
-      wd = resolve(wd, '..');
-      devConfigPath = resolve(wd, devConfigName);
-      configPath = resolve(wd, configName);
+      if (wd === REPO_ROOT) {
+        break;
+      }
+
+      const parent = resolve(wd, '..');
+      if (parent === wd) {
+        break;
+      }
+
+      wd = parent;
     }
 
-    if (existsSync(devConfigPath)) {
-      configPath = devConfigPath;
+    if (!configPath) {
+      if (testFilesProvided) {
+        log.error(
+          `unable to find a ${configName} file in ${commonTestFiles} or any parent directory up to the root of the repo. This CLI can only run Jest tests which resolve to a single ${configName} file, and that file must exist in a parent directory of all the paths you pass.`
+        );
+      } else {
+        log.error(
+          `we no longer ship a root config file so you either need to pass a path to a test file, a folder where tests can be found, or a --config argument pointing to one of the many ${configName} files in the repository`
+        );
+      }
+
+      process.exit(1);
     }
 
     log.verbose(`no config provided, found ${configPath}`);