[testing/nodejs] Support gathering coverage data.

- Update istanbul and mocha to their most recent versions. The istanbul
  CLI has been replaced by the nyc CLI. This is required in order to
  exclude tests from test sets and to exclude certain files (closure
  cases) from instrumentation.
- Add support for gathering and reporting coverage data under the
  `PULUMI_TEST_COVERAGE_PATH` environment variable.

sdk/nodejs/.gitignore

@@ -4,3 +4,4 @@
 /node_modules/
 /custom_node/
 /runtime/native/node_dev/
+.nyc_output/

sdk/nodejs/Makefile

@@ -46,25 +46,28 @@ install_plugin:: build
 
 install:: install_package install_plugin
 
-istanbul_tests:: $(TEST_ALL_DEPS)
-	$(RUN_TESTSUITE) istanbul ./node_modules/.bin/istanbul test --print none _mocha -- --timeout 120000 --exclude 'bin/tests/automation/**/*.spec.js' 'bin/tests/**/*.spec.js'
-	./node_modules/.bin/istanbul report text-summary
-	./node_modules/.bin/istanbul report text
-	$(RUN_TESTSUITE) istanbul-with-mocks ./node_modules/.bin/istanbul test --print none _mocha -- 'bin/tests_with_mocks/**/*.spec.js'
+unit_tests:: $(TEST_ALL_DEPS)
+	$(RUN_TESTSUITE) unit-nodejs ./node_modules/.bin/nyc -x 'bin/tests/runtime/*ClosureCases*.js' -s mocha --timeout 120000 --exclude 'bin/tests/automation/**/*.spec.js' --exclude 'bin/tests/runtime/closureLoader.spec.js' 'bin/tests/**/*.spec.js'
+	$(RUN_TESTSUITE) unit-nodejs mocha --timeout 120000 'bin/tests/runtime/closureLoader.spec.js'
+	$(RUN_TESTSUITE) unit-with-mocks-nodejs ./node_modules/.bin/nyc -s mocha 'bin/tests_with_mocks/**/*.spec.js'
 
 auto_tests:: $(TEST_ALL_DEPS)
-	$(RUN_TESTSUITE) auto-nodejs ./node_modules/.bin/istanbul test --print none _mocha -- --timeout 120000 'bin/tests/automation/**/*.spec.js'
-	./node_modules/.bin/istanbul report text-summary
-	./node_modules/.bin/istanbul report text
+	$(RUN_TESTSUITE) auto-nodejs ./node_modules/.bin/nyc -s mocha --timeout 120000 'bin/tests/automation/**/*.spec.js'
 
 sxs_tests:: $(TEST_ALL_DEPS)
 	pushd tests/sxs_ts_3.6 && yarn ; tsc ; popd
 	pushd tests/sxs_ts_latest && yarn ; tsc ; popd
 
-test_fast:: sxs_tests istanbul_tests
+test_fast:: sxs_tests unit_tests
+ifneq ($(PULUMI_TEST_COVERAGE_PATH),)
+	if [ -e .nyc_output ]; then ./node_modules/.bin/nyc report -r cobertura --report-dir $(PULUMI_TEST_COVERAGE_PATH); fi
+endif
 	$(GO_TEST_FAST) ${PROJECT_PKGS}
 
-test_all:: sxs_tests istanbul_tests auto_tests
+test_all:: sxs_tests unit_tests auto_tests
+ifneq ($(PULUMI_TEST_COVERAGE_PATH),)
+	if [ -e .nyc_output ]; then ./node_modules/.bin/nyc report -r cobertura --report-dir $(PULUMI_TEST_COVERAGE_PATH); fi
+endif
 	$(GO_TEST) ${PROJECT_PKGS}
 
 dist:: build

sdk/nodejs/package.json

@@ -39,13 +39,16 @@
         "eslint": "^7.32.0",
         "eslint-plugin-header": "^3.1.1",
         "eslint-plugin-import": "^2.23.4",
-        "istanbul": "^0.4.5",
-        "mocha": "^3.5.0"
+        "nyc": "^15.1.0",
+        "mocha": "^9.0.0"
     },
     "pulumi": {
         "comment": "Do not remove. Marks this as as a deployment-time-only package"
     },
     "engines": {
         "node": ">=8.13.0 || >=10.10.0"
+    },
+    "mocha": {
+        "require": ["ts-node/register", "source-map-support/register"]
     }
 }

sdk/nodejs/tsconfig.json

@@ -6,7 +6,7 @@
         "module": "commonjs",
         "moduleResolution": "node",
         "declaration": true,
-        "sourceMap": false,
+        "sourceMap": true,
         "stripInternal": true,
         "experimentalDecorators": true,
         "pretty": true,