Bug 1698074, follow-up for prettier and diff (#1896)

* Bump diff file limit to make diff work.
* Prettified version from flow-to-ts strips newlines - move the prettier call separate.
* Rewire prettier to ts(x) in frontend.

.github/workflows/frontend.yml

@@ -67,25 +67,30 @@ jobs:
       - name: Install globals
         run: |
           npm install -g yarn @khanacademy/flow-to-ts
+      - name: npm install
+        run: npm install
       - name: Pre-flight switches
         working-directory: frontend
         run: |
           yarn remove flow-bin
           yarn add -D typescript @types/jest @types/node @types/react @types/react-dom
+      - name: Redirect prettier
+        run: |
+          python -c "from pathlib import Path;pack_path=Path('package.json');pack_path.write_text(pack_path.read_text().replace('**/frontend/**/*.{js,css}','**/frontend/**/*.{ts,tsx,css}'))"
       - name: Pre-flight diff
         run: git diff
       - name: Pre-flight commit
         run: git commit -am"Pre-flight flow to ts"
       - name: flow-to-ts
-        working-directory: frontend
-        run: flow-to-ts --prettier --write --delete-source 'src/**/*.js'
-      # Git diff doesn't do anything constructive on gh actions, disable for now
-      # - name: Stage
-      #   run: |
-      #     git add frontend
-      #     git commit -m'flow-to-ts'
-      # - name: flow-to-ts diff
-      #   run: git show HEAD
+        run: flow-to-ts --write --delete-source 'frontend/src/**/*.js'
+      - name: prettier
+        run: npm run prettier
+      - name: Stage
+        run: |
+          git add frontend
+          git commit -m'flow-to-ts'
+      - name: flow-to-ts diff
+        run: git -c diff.renameLimit=36000 show HEAD
       - name: tsc
         working-directory: frontend
         run: ./node_modules/.bin/tsc -b no-tsconfig.json