Give up, use babel

Makefile

@@ -100,7 +100,7 @@ js-test:
 	npx jest
 
 js-coverage:
-	npx jest --coverage --collectCoverageFrom="./ambuda/src/js/**"
+	npx jest --coverage
 
 # Lint our JavaScript code.
 # FIXME(arun): typescript lint

babel.config.js

@@ -0,0 +1,7 @@
+// FIXME(???): switch to esbuild for consistency with prod
+module.exports = {
+  presets: [
+      ['@babel/preset-env', {targets: {node: 'current'}}],
+      "@babel/preset-typescript",
+  ],
+};

jest.config.js

@@ -4,20 +4,25 @@
  */
 
 module.exports = {
+  collectCoverageFrom: [
+    "ambuda/static/js/*.{js,ts}",
+  ],
   // Indicates whether the coverage information should be collected while executing the test
   coverageDirectory: "js-coverage-report",
-  // Use '@' to refer to the root folder that contains all source modules. 
+  coverageThreshold: {
+    global: {
+      statements: 20,
+      branches: 20,
+      functions: 20,
+      lines: 20,
+    }
+  },
+  // Use '@' to refer to the root folder that contains all source modules.
   moduleNameMapper: {
     "^@/(.*)": "<rootDir>/ambuda/static/js/$1",
   },
   roots: [
-  	"<rootDir>/test/js/",
+    "<rootDir>/test/js/",
   ],
   testEnvironment: "jsdom",
-  // Build all test code with esbuild, for consistency with prod.
-  transform: {
-    "\\.[jt]s$": [
-      "<rootDir>/test/TransformerEsbuild.js",
-    ],
-  },
 };