Parallel: Disallow calls to Env#config from spec and helper files

Such configuration changes only affect one worker, which is almost certainly
not the intent.

lib/jasmine-core/jasmine.js

@@ -1309,6 +1309,12 @@ getJasmineRequireObj().Env = function(j$) {
      * @function
      */
     this.configure = function(configuration) {
+      if (parallelLoadingState) {
+        throw new Error(
+          'Jasmine cannot be configured via Env in parallel mode'
+        );
+      }
+
       const booleanProps = [
         'random',
         'failSpecWithNoExpectations',

spec/core/EnvSpec.js

@@ -758,16 +758,16 @@ describe('Env', function() {
 
     describe('In parallel mode', function() {
       it('rejects if random is set to false', async function() {
-        env.setParallelLoadingState('specs');
         env.configure({ random: false });
+        env.setParallelLoadingState('specs');
         await expectAsync(env.execute()).toBeRejectedWithError(
           'Randomization cannot be disabled in parallel mode'
         );
       });
 
       it('rejects if seed is set', async function() {
-        env.setParallelLoadingState('specs');
         env.configure({ seed: 1234 });
+        env.setParallelLoadingState('specs');
         await expectAsync(env.execute()).toBeRejectedWithError(
           'Random seed cannot be set in parallel mode'
         );
@@ -817,4 +817,18 @@ describe('Env', function() {
       }).toThrowError('Reporters cannot be removed via Env in parallel mode');
     });
   });
+
+  describe('#configure', function() {
+    it('throws when called in parallel mode', function() {
+      env.setParallelLoadingState('helpers');
+      expect(function() {
+        env.configure({});
+      }).toThrowError('Jasmine cannot be configured via Env in parallel mode');
+
+      env.setParallelLoadingState('specs');
+      expect(function() {
+        env.configure({});
+      }).toThrowError('Jasmine cannot be configured via Env in parallel mode');
+    });
+  });
 });

src/core/Env.js

@@ -174,6 +174,12 @@ getJasmineRequireObj().Env = function(j$) {
      * @function
      */
     this.configure = function(configuration) {
+      if (parallelLoadingState) {
+        throw new Error(
+          'Jasmine cannot be configured via Env in parallel mode'
+        );
+      }
+
       const booleanProps = [
         'random',
         'failSpecWithNoExpectations',