feat: Test coverage support

This commit lays the foundation for displaying coverage results
from `bazel coverage`.

For the time being, the functionality is only exposed through the
user-defined tasks in the `tasks.json`. It is thereby a bit hard to
discover. But this is fine for the time being, because coverage still
has a couple of rough edges anyway. As soon as it is more stable, we
should add builtin commands and expose coverage runs also in the "Bazel
Build Target" tree.

Changes in this commit:
* Bumps the VS Code version to 1.88, i.e. the first VS Code version
  which supports the test coverage API.
* Upgrades to ES2022.  I wanted to use `replaceAll` which was introduced
  in ES2021.
  VS Code 1.88 is based on Node 18 which in turn is based on V8 10.1. V8
  10.18 supports ECMA-262 also known as ES2023.  However, ES2023 is not
  yet available a target language in the `tsconfig.json`.  Furthermore,
  Firefox does not fully support ES2023, yet. While web browsers are
  currently not relevant, they might become so in the future if we want
  to turn this into a browser-enabled VSCode extension.
  An upgrade to ES2021 would have been sufficient, but I went directly
  to ES2022 because it might some of the other new features might also
  turn out useful.
* Introduces a custom LCOV parser. I could not find any other
  high-quality open-source parser. E.g., most other parser don't
  properly parse function names with `:` and / or `,` in them.
* Introduces test cases for that custom LCOV parser.

Future work:
* Support for branch coverage
* Demangling of function names
* Builtin commands to trigger coverage runs & offer them in the "Bazel
  Build Tree"

Tested with: Java, C++, Go, Rust
Untested: Python, Swift, Kotlin, Scala and many more

This is the first step towards bazel-contrib#362

.bazelci/presubmit.yml

@@ -13,11 +13,14 @@ tasks:
         echo "deb [signed-by=/etc/apt/keyrings/nodesource.gpg] https://deb.nodesource.com/node_$NODE_MAJOR.x nodistro main" | sudo tee /etc/apt/sources.list.d/nodesource.list
         sudo apt-get update
         sudo apt-get install nodejs -y
+      # Required for vscode-test
+      - sudo apt install -y libasound2 libgbm1 libgtk-3-0 libnss3 xvfb
       # Install node_modules and then compile and check the code for lint
       # errors.
       - npm ci
       - npm run compile
       - npm run check-lint
+      - xvfb-run -a npm run test
       # TODO(allevato): Add a prettier check to verify that *.ts files don't
       # differ from their prettier output. We need `prettier-tslint` so that
       # prettier will obey our tslint config, but it doesn't support

.gitignore

@@ -1,5 +1,6 @@
 out
 node_modules
+.vscode-test
 *.vsix
 
 # Ignore the generated .d.ts and .js files for protos that end up in the src/

.vscode-test.js

@@ -0,0 +1,6 @@
+const { defineConfig } = require('@vscode/test-cli');
+
+module.exports = defineConfig({
+    files: "out/test/**/*.test.js",
+    mocha: { ui: "bdd" },
+  });

.vscodeignore

@@ -4,6 +4,7 @@ out/test/**
 scripts/**
 src/**
 test/**
+.vscode-test/
 
 **/*.map
 

README.md

@@ -14,6 +14,8 @@ This extension provides support for Bazel in Visual Studio.
 - **Buildifier** integration to lint and format your Bazel files (requires that
   [Buildifier](https://github.com/bazelbuild/buildtools/releases) be installed)
 - **Bazel Task** definitions for `tasks.json`
+- **Coverage Support** showing coverage results from `bazel coverage` directly
+  in VS Code.
 - Debug Starlark code in your `.bzl` files during a build (set breakpoints, step
   through code, inspect variables, etc.)
 
@@ -61,7 +63,7 @@ This extension can use [Facebook's starlark project](https://github.com/facebook
 
 Bazel tasks can be configured from the `tasks.json` using the following structure:
 
-```json
+```jsonc
 {
   // See https://go.microsoft.com/fwlink/?LinkId=733558
   // for the documentation about the tasks.json format
@@ -89,6 +91,36 @@ Bazel tasks can be configured from the `tasks.json` using the following structur
 }
 ```
 
+## Coverage support (Experimental)
+
+For all `coverage` tasks, the coverage results are automatically loaded into VS
+Code upon completion of the task. E.g., you could define your own task to
+display the coverage provided by your integration tests using the following task
+definition:
+
+```jsonc
+{
+  "label": "Show test coverage from integration test",
+  "type": "bazel",
+  "command": "coverage",
+  "targets": ["//test/integration/...", "//cpp/test/integration/..."],
+  "options": ["--instrumentation_filter=.*"]
+}
+```
+
+You might need additional Bazel `options` to get the intended coverage results.
+In particular if are using remote builds, you might need to use the
+`--experimental_split_coverage_postprocessing` and `--experimental_fetch_all_coverage_outputs`
+options. See the documentation on [Code Coverage with Bazel](https://bazel.build/configure/coverage)
+for more details.
+
+Code coverage support in this extension is still rather fresh and might still
+have rough edges. It was tested with the Java, C++, Go and Rust rules.
+In case you are using the code coverage integration with any other language
+(Python, Swift, Kotlin, Scala, ...), please let us know how things are going in
+bazelbuild/vscode-bazel#367. Please share both positive and negative experiences
+you might have.
+
 ## Contributing
 
 If you would like to contribute to the Bazel Visual Studio extension, please