feat: add code coverage

.github/workflows/check.yml

@@ -11,6 +11,12 @@ concurrency:
 
 jobs:
   check:
+    permissions:
+      pull-requests: write
+      id-token: write
+      pages: write
+      checks: write
+
     runs-on: ubuntu-24.04-8core-bakunin
 
     steps:
@@ -49,3 +55,60 @@ jobs:
           RUST_BACKTRACE: 1
           SKIP_WASM_BUILD: 1
         run: cargo test
+
+      - uses: jwalton/gh-find-current-pr@v1
+        id: findPr
+
+      - name: Install cargo-llvm-cov
+        if: success() && steps.findPr.outputs.number
+        uses: taiki-e/install-action@cargo-llvm-cov
+
+      - name: Install cargo-xtask
+        if: success() && steps.findPr.outputs.number
+        run: cargo install cargo-xtask
+
+      - name: Generate code coverage lcov
+        if: success() && steps.findPr.outputs.number
+        run: cargo xtask coverage
+
+      - name: Generate code coverage html
+        if: success() && steps.findPr.outputs.number
+        run: cargo xtask coverage --html
+
+      - name: Upload html coverage report
+        if: success() && steps.findPr.outputs.number
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: 'target/llvm-cov/html'
+
+      - name: Deploy to GitHub Pages
+        if: success() && steps.findPr.outputs.number
+        id: deployment
+        uses: actions/deploy-pages@v4
+
+      - name: Generate Coverage Summary Report
+        if: success() && steps.findPr.outputs.number
+        uses: irongut/[email protected]
+        with:
+          filename: target/cov.xml
+          badge: true
+          format: markdown
+          hide_branch_rate: false
+          # hide_complexity: true
+          indicators: true
+          output: both
+
+      - name: Append github pages link to report
+        if: success() && steps.findPr.outputs.number
+        run: echo '\n\n[Detailed coverage report]($GITHUB_PAGES_LINK)' &>> code-coverage-results.md
+        env:
+          GITHUB_PAGES_LINK: ${{ steps.deployment.page_url}}
+
+      - name: Add Coverage PR Comment
+        if: success() && steps.findPr.outputs.number
+        uses: marocchino/sticky-pull-request-comment@v2
+        with:
+          number: ${{ steps.finder.outputs.pr }}
+          recreate: true
+          path: code-coverage-results.md
+

.vscode/settings.json

@@ -2,7 +2,16 @@
   // Editor
   "editor.formatOnSave": true,
   // Rust
-  "rust-analyzer.cargo.extraEnv": { "SKIP_WASM_BUILD": "1" },
-  "rust-analyzer.check.extraEnv": { "SKIP_WASM_BUILD": "1" },
-  "rust-analyzer.cargo.features": ["runtime-benchmarks"]
-}
+  "rust-analyzer.cargo.extraEnv": {
+    "SKIP_WASM_BUILD": "1"
+  },
+  "rust-analyzer.check.extraEnv": {
+    "SKIP_WASM_BUILD": "1"
+  },
+  "rust-analyzer.cargo.features": [
+    "runtime-benchmarks"
+  ],
+  "coverage-gutters.coverageFileNames": [
+    "target/info.lcov",
+  ],
+}

flake.nix

@@ -37,6 +37,8 @@
           pkgs.act
           # Python
           pkgs.python310
+          # Code coverage tool
+          pkgs.cargo-llvm-cov
         ];
       in
       {

rust-toolchain.toml

@@ -6,6 +6,6 @@
 # but we use the oxalica overlay, which does not fix this yet.
 # Should be fixed by https://github.com/rust-lang/rust/issues/123151.
 channel = "1.82.0"
-components = ["clippy", "rustfmt", "rust-src", "rust-analyzer"]
+components = ["clippy", "rustfmt", "rust-src", "rust-analyzer", "llvm-tools-preview"]
 targets = ["x86_64-unknown-linux-gnu", "wasm32-unknown-unknown"]
 profile = "minimal"

xtask/src/flags.rs

@@ -61,6 +61,10 @@ xflags::xflags! {
 
             optional --sudo sudo_key: String
         }
+
+        cmd coverage {
+            optional --html
+        }
     }
 }
 
@@ -76,6 +80,7 @@ pub struct Xtask {
 pub enum XtaskCmd {
     Run(Run),
     GenerateSpec(GenerateSpec),
+    Coverage(Coverage),
 }
 
 #[derive(Debug)]
@@ -114,6 +119,11 @@ pub struct GenerateSpec {
     pub sudo: Option<String>,
 }
 
+#[derive(Debug)]
+pub struct Coverage {
+    pub html: bool,
+}
+
 impl Xtask {
     #[allow(dead_code)]
     pub fn from_env_or_exit() -> Self {

xtask/src/main.rs

@@ -1,4 +1,4 @@
-use std::{borrow::Cow, net::IpAddr, path::Path};
+use std::{borrow::Cow, net::IpAddr, os::unix::process::CommandExt, path::Path};
 
 use polkadot_sdk::sp_keyring;
 
@@ -75,6 +75,27 @@ fn main() {
 
             std::fs::write(cmd.out, out).expect("failed to write resulting ");
         }
+        flags::XtaskCmd::Coverage(coverage) => {
+            const PALLETS: [&str; 3] = ["pallet-emission0", "pallet-governance", "pallet-torus0"];
+
+            let mut cmd = std::process::Command::new("cargo");
+            let mut args = vec!["llvm-cov", "--all-features"];
+
+            for pallet in PALLETS {
+                args.extend_from_slice(&["-p", pallet]);
+            }
+
+            if coverage.html {
+                let dev_args = ["--html"];
+                args.extend_from_slice(&dev_args);
+            } else {
+                let ci_args = ["--cobertura", "--output-path", "target/cov.xml"];
+                args.extend_from_slice(&ci_args);
+            }
+
+            cmd.args(args);
+            cmd.exec();
+        }
     }
 }