coverage: add coverage CI action

.github/workflows/kcov.yml

@@ -0,0 +1,46 @@
+name: Code Coverage
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+
+permissions:
+  pull-requests: write
+
+jobs:
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+          submodules: true
+
+      - uses: goto-bus-stop/setup-zig@v2
+        with:
+          version: master
+
+      - run: zig version
+      - run: zig env
+
+      - name: Build
+        run: zig build
+
+      - name: Install kcov
+        run: |
+          sudo apt-get update
+          sudo apt-get install kcov
+
+      - name: Run Tests with kcov
+        run: |
+          mkdir -p zig-out/kcov
+          zig build test -Dgenerate_coverage
+          
+      - uses: actions/checkout@master
+      - uses: codecov/codecov-action@v3
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          directory: zig-out/kcov/kcov-merged
+          fail_ci_if_error: true
+          verbose: true
+

build.zig

@@ -216,31 +216,46 @@ pub fn build(b: *std.build.Builder) !void {
     if (coverage) {
         const include_pattern = b.fmt("--include-pattern=/src", .{});
         const exclude_pattern = b.fmt("--exclude-pattern=/src/stage2", .{});
-        const args = &[_]std.build.RunStep.Arg{
-            .{ .bytes = b.dupe("kcov") },
-            .{ .bytes = b.dupe("--collect-only") },
-            .{ .bytes = b.dupe(include_pattern) },
-            .{ .bytes = b.dupe(exclude_pattern) },
-            .{ .bytes = b.dupe(coverage_output_dir) },
-        };
 
         var tests_run = b.addRunArtifact(tests);
         var src_tests_run = b.addRunArtifact(src_tests);
         tests_run.has_side_effects = true;
         src_tests_run.has_side_effects = true;
 
-        tests_run.argv.insertSlice(0, args) catch @panic("OOM");
-        src_tests_run.argv.insertSlice(0, args) catch @panic("OOM");
+        tests_run.argv.insertSlice(0, &[_]std.build.RunStep.Arg{
+            .{ .bytes = b.dupe("kcov") },
+            .{ .bytes = b.dupe(include_pattern) },
+            .{ .bytes = b.dupe(exclude_pattern) },
+            .{ .bytes = b.pathJoin(&.{ coverage_output_dir, "test-tests" }) },
+        }) catch @panic("OOM");
+
+        src_tests_run.argv.insertSlice(0, &[_]std.build.RunStep.Arg{
+            .{ .bytes = b.dupe("kcov") },
+            .{ .bytes = b.dupe(include_pattern) },
+            .{ .bytes = b.dupe(exclude_pattern) },
+            .{ .bytes = b.pathJoin(&.{ coverage_output_dir, "test-src" }) },
+        }) catch @panic("OOM");
 
         var merge_step = std.build.RunStep.create(b, "merge kcov");
         merge_step.has_side_effects = true;
+
         merge_step.addArgs(&.{
             "kcov",
             "--merge",
+        });
+
+        if (b.env_map.get("COVERALLS_REPO_TOKEN")) |repo_token| {
+            std.log.info("Detected repo token; enabling automatic upload to Coveralls", .{});
+            merge_step.addArg(std.mem.concat(b.allocator, u8, &[_][]const u8{ "--coveralls-id=", repo_token }) catch @panic("OOM"));
+        }
+
+        merge_step.addArgs(&.{
             coverage_output_dir,
-            b.pathJoin(&.{ coverage_output_dir, "test" }),
+            b.pathJoin(&.{ coverage_output_dir, "test-tests" }),
+            b.pathJoin(&.{ coverage_output_dir, "test-src" }),
         });
-        merge_step.step.dependOn(&b.addRemoveDirTree(coverage_output_dir).step);
+
+        // merge_step.step.dependOn(&b.addRemoveDirTree(coverage_output_dir).step);
         merge_step.step.dependOn(&tests_run.step);
         merge_step.step.dependOn(&src_tests_run.step);
         test_step.dependOn(&merge_step.step);