Fix jestTransformer for moved cache + config firs

Partially addresses piglovesyou#605 

Sets a new cwd context in cases where the config file does not reside in the jest root directory. This is necessary because the config file can then give the cache location, but it will be relative to its own location (not that of the jest config)

src/jestTransformer.ts

@@ -1,11 +1,11 @@
 import { SyncTransformer } from '@jest/transform';
 import { ProjectConfig } from '@jest/types/build/Config';
 import { readFileSync } from 'fs';
-import { relative } from 'path';
 import { loadConfigSync } from './lib/config';
 import { createExecContextSync } from './lib/exec-context';
 import { createHash } from './lib/hash';
 import { createPaths } from './lib/paths';
+import { dirName, relative, resolve } from 'path';
 
 export type JestTransformerOptions = {
   configFile?: string;
@@ -38,8 +38,11 @@ const jestTransformer: SyncTransformer<JestTransformerOptions> = {
     const [__compatJestConfig] = rest;
     const jestConfig = __compatJestConfig?.config ?? __compatJestConfig;
     // jest v26 vs v27 changes to support both formats: end
-    const { rootDir: cwd } = jestConfig;
+    let { rootDir: cwd } = jestConfig;
     const { configFile, subsequentTransformer } = getOption(jestConfig);
+    // If the congFile is in another directory from jest's rootDir, reset the working path since
+    // since the cache and transforms will operate relative to that config's location
+    const cwd = resolve(cwd, dirname(configFile));
     const [config, configHash] = loadConfigSync(cwd, configFile);
     const { execContext } = createExecContextSync(cwd, config, configHash);