test(screenshotter): move coverage to Jest (#2324)

* Move screenshotter coverage collection to Jest testing

Fixes #1885.

* Update screenshotter-spec.js

* Update screenshotter-spec.js

Co-authored-by: Kevin Barabash <kevinb@khanacademy.org>

.circleci/config.yml

@@ -43,16 +43,6 @@ commands:
           paths:
             - node_modules
 
-  codecov:
-    parameters:
-      flag:
-        type: string
-    steps:
-      - run:
-          name: Upload code coverage reports to Codecov
-          # do not upload if screenshotter tests are skipped
-          command: ./node_modules/.bin/codecov -F "<< parameters.flag >>"
-
 jobs:
   test:
     docker:
@@ -81,8 +71,9 @@ jobs:
           command: |
               yarn test:flow
               yarn test:jest --coverage --runInBand
-      - codecov:
-          flag: test
+      - run:
+          name: Upload code coverage reports to Codecov
+          command: ./node_modules/.bin/codecov
 
   screenshotter:
     parameters:
@@ -97,9 +88,7 @@ jobs:
 
       - run:
           name: Verify screenshots and generate diffs and new screenshots
-          command: node dockers/screenshotter/screenshotter.js --selenium-ip localhost -b $CIRCLE_JOB --verify --diff --new --coverage
-      - codecov:
-          flag: screenshotter
+          command: node dockers/screenshotter/screenshotter.js --selenium-ip localhost -b $CIRCLE_JOB --verify --diff --new
       - store_artifacts:
           path: test/screenshotter/new
           destination: new

test/screenshotter-spec.js

@@ -0,0 +1,19 @@
+const data = require("./screenshotter/ss_data");
+
+describe("Screenshotter item", function() {
+    for (const key in data) {
+        if (data.hasOwnProperty(key)) {
+            const item = data[key];
+            it(`"${item.tex}" should build successfully`, function() {
+                expect(item.tex).toBuild({
+                    macros: item.macros,
+                    displayMode: item.display,
+                    throwOnError: !item.noThrow,
+                    errorColor: item.errorColor,
+                    strict: false,
+                    trust: true,  // trust test inputs
+                });
+            });
+        }
+    }
+});