From 25338ee38ff2c471ff7df9b018eceb7fbefa830e Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Thu, 22 Sep 2022 15:27:17 +0200
Subject: [PATCH 1/3] Add optional test coverage reports

---
 .c8rc.json        | 17 +++++++++++++++++
 .gitignore        |  1 +
 package.json      |  1 +
 tests/compiler.js |  5 +++--
 4 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 .c8rc.json

diff --git a/.c8rc.json b/.c8rc.json
new file mode 100644
index 0000000000..fde64f42b6
--- /dev/null
+++ b/.c8rc.json
@@ -0,0 +1,17 @@
+{
+  "reporter": ["html", "text"],
+  "reportsDirectory": "./coverage",
+  "src": ["src"],
+  "exclude": [
+    "std/**/*",
+    "tests/**/*",
+    "dist/**/*",
+    "bin/asinit.js",
+    "lib/**/*",
+    "scripts/**/*",
+    "src/glue/wasm/**/*",
+    "util/browser/**/*"
+  ],
+  "clean": true,
+  "exclude-after-remap": true
+}
diff --git a/.gitignore b/.gitignore
index 98a3ba835b..3166d113d2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,4 @@ raw/
 .idea
 cli/index.generated.js
 src/diagnosticMessages.generated.ts
+coverage/
diff --git a/package.json b/package.json
index bc3bd45d64..6c93b22e33 100644
--- a/package.json
+++ b/package.json
@@ -70,6 +70,7 @@
     "lint": "eslint --max-warnings 0 --ext js . && eslint --max-warnings 0 --ext ts .",
     "build": "node scripts/build",
     "watch": "node scripts/build --watch",
+    "coverage": "npx c8 -- npm test",
     "test": "npm run test:parser && npm run test:compiler -- --parallel && npm run test:browser && npm run test:asconfig && npm run test:transform",
     "test:parser": "node --enable-source-maps tests/parser",
     "test:compiler": "node --enable-source-maps --no-warnings tests/compiler",
diff --git a/tests/compiler.js b/tests/compiler.js
index 84cf0928f7..5280a3e47a 100644
--- a/tests/compiler.js
+++ b/tests/compiler.js
@@ -492,8 +492,9 @@ function evaluateResult(failedTests, skippedTests) {
   }
 }
 
-// Run tests in parallel if requested
-if (args.parallel && coreCount > 2) {
+// Run tests in parallel if requested (except with coverage)
+const isCoverage = process.env.NODE_V8_COVERAGE != null;
+if (!isCoverage && args.parallel && coreCount > 2) {
   if (cluster.isWorker) {
     process.on("message", msg => {
       if (msg.cmd != "run") throw Error("invalid command: " + JSON.stringify(msg));

From 2362eb70faa93aa78e5d14e8076241039697dc78 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Fri, 23 Sep 2022 17:09:38 +0200
Subject: [PATCH 2/3] document

---
 tests/README.md | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/tests/README.md b/tests/README.md
index 3bbaef5656..b6e82e50a8 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -116,6 +116,18 @@ Features
 
 Tests for experimental features (usually enabled via the `--enable` CLI flag) are disabled by default. To enable a feature, set the `ASC_FEATURES` environment variable to a comma-separated list of feature names (see [`features.json`](./features.json)). You can also set `ASC_FEATURES="*"` to enable all features.
 
+Coverage
+--------
+
+An optional code coverage report can be generated by running
+
+```
+$> npm install c8
+$> npm run coverage
+```
+
+Code coverage runs the tests with [c8](https://github.com/bcoe/c8) using the JS variant of the compiler. It is expected that Wasm-only branches show as untaken. Make sure to enable all (relevant) [features](#features).
+
 Other
 -----
 

From e41e8835d7a1486676cb6e19a78540e2dcffe1bc Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Fri, 23 Sep 2022 17:11:28 +0200
Subject: [PATCH 3/3] mention HTML report

---
 tests/README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/README.md b/tests/README.md
index b6e82e50a8..0163048a04 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -126,7 +126,7 @@ $> npm install c8
 $> npm run coverage
 ```
 
-Code coverage runs the tests with [c8](https://github.com/bcoe/c8) using the JS variant of the compiler. It is expected that Wasm-only branches show as untaken. Make sure to enable all (relevant) [features](#features).
+Code coverage runs the tests with [c8](https://github.com/bcoe/c8) using the JS variant of the compiler. It is expected that Wasm-only branches show as untaken. Make sure to enable all (relevant) [features](#features). A convenient HTML report is generated to `coverage/`.
 
 Other
 -----