GH actions: use source-based coverage

.github/workflows/rust.yml

@@ -1,10 +1,6 @@
 name: svg2gcode
 
-on:
-  push:
-    branches: [ master ]
-  pull_request:
-    branches: [ master ]
+on: [push, pull_request]
 
 env:
   CARGO_TERM_COLOR: always
@@ -13,21 +9,42 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - name: Build
         run: cargo build
-      - name: Run cargo-tarpaulin
-        uses: actions-rs/tarpaulin@v0.1
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
         with:
-          version: '0.14.2'
-          args: '-- --nocapture --test-threads 1'
-      - name: Upload to codecov.io
-        uses: codecov/codecov-action@v1
+          fetch-depth: 0
+      - uses: actions-rs/toolchain@v1
         with:
-          token: ${{secrets.CODECOV_TOKEN}}
-
-      - name: Archive code coverage results
-        uses: actions/upload-artifact@v1
+          toolchain: nightly
+          override: true
+          profile: minimal
+          components: llvm-tools-preview
+      - uses: actions-rs/install@v0.1
+        with:
+          crate: grcov
+          version: 0.7.1
+          use-tool-cache: true
+      - uses: actions-rs/cargo@v1
         with:
-          name: code-coverage-report
-          path: cobertura.xml
+          command: build
+        env:
+          RUSTFLAGS: '-Zinstrument-coverage'
+          RUSTDOCFLAGS: '-Zinstrument-coverage'
+      - uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --all-features --no-fail-fast
+        env:
+          RUSTFLAGS: '-Zinstrument-coverage'
+          RUSTDOCFLAGS: '-Zinstrument-coverage'
+          LLVM_PROFILE_FILE: 'codecov-instrumentation-%p-%m.profraw'
+      - name: grcov
+        run: grcov . -s . --binary-path ./target/debug/ -t lcov --branch -o lcov.info
+      - uses: codecov/codecov-action@v1
+        with:
+          token: ${{secrets.CODECOV_TOKEN}}