Merge pull request #6810 from metabase/upgrade-to-jest-21-2-1

Reduce number of Jest test runner worker threads

frontend/test/metabase-lib/Mode.unit.spec.js

@@ -22,7 +22,7 @@ describe("Mode", () => {
         .mode();
 
     describe("forQuestion(question)", () => {
-        it("with structured query question", () => {
+        describe("with structured query question", () => {
             // testbed for generative testing? see http://leebyron.com/testcheck-js
 
             it("returns `segment` mode with raw data", () => {});
@@ -39,11 +39,11 @@ describe("Mode", () => {
             it("returns `default` mode with >=0 aggregations and >=3 breakouts", () => {});
             it("returns `default` mode with >=1 aggregations and >=1 breakouts when first neither date or category", () => {});
         });
-        it("with native query question", () => {
+        describe("with native query question", () => {
             it("returns `NativeMode` for empty query", () => {});
             it("returns `NativeMode` for query with query text", () => {});
         });
-        it("with oddly constructed query", () => {
+        describe("with oddly constructed query", () => {
             it("should throw an error", () => {
                 // this is not the actual behavior atm (it returns DefaultMode)
             });

package.json

@@ -158,7 +158,7 @@
     "test": "yarn run test-integrated && yarn run test-unit && yarn run test-karma",
     "test-integrated": "babel-node ./frontend/test/__runner__/run_integrated_tests.js",
     "test-integrated-watch": "babel-node ./frontend/test/__runner__/run_integrated_tests.js --watch",
-    "test-unit": "jest --maxWorkers=10 --config jest.unit.conf.json --coverage",
+    "test-unit": "jest --maxWorkers=8 --config jest.unit.conf.json --coverage",
     "test-unit-watch": "jest --maxWorkers=10 --config jest.unit.conf.json --watch",
     "test-unit-update-snapshot": "jest --maxWorkers=10 --config jest.unit.conf.json --updateSnapshot",
     "test-karma": "karma start frontend/test/karma.conf.js --single-run",