Add covr (#51)

Author: chainsawriot

.Rbuildignore

@@ -6,3 +6,5 @@
 ^docs$
 ^pkgdown$
 ^\.github$
+^.editorconfig$
+^.codecov.yml$

.codecov.yml

@@ -0,0 +1,3 @@
+coverage:
+  status:
+    patch: off

.editorconfig

@@ -0,0 +1,16 @@
+root = true
+
+
+[*]
+charset = utf8
+end_of_line = lf
+insert_final_newline = true
+indent_style = space
+
+
+[*.{r,R, rmd, Rmd}]
+indent_size = 4
+trim_trailing_whitespace = true
+
+[Makefile]
+indent_style = tab

.github/workflows/test-coverage.yaml

@@ -0,0 +1,52 @@
+# Workflow derived from https://github.com/r-lib/actions/tree/v2/examples
+# Need help debugging build failures? Start at https://github.com/r-lib/actions#where-to-find-help
+on:
+  push:
+    branches:
+      - v*
+  pull_request:
+    branches:
+      - v*
+
+name: test-coverage
+
+jobs:
+  test-coverage:
+    runs-on: ubuntu-latest
+    env:
+      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - uses: r-lib/actions/setup-r@v2
+        with:
+          use-public-rspm: true
+
+      - uses: r-lib/actions/setup-r-dependencies@v2
+        with:
+          extra-packages: any::covr
+          needs: coverage
+
+      - name: Test coverage
+        run: |
+          covr::codecov(
+            quiet = FALSE,
+            clean = FALSE,
+            install_path = file.path(normalizePath(Sys.getenv("RUNNER_TEMP"), winslash = "/"), "package")
+          )
+        shell: Rscript {0}
+
+      - name: Show testthat output
+        if: always()
+        run: |
+          ## --------------------------------------------------------------------
+          find ${{ runner.temp }}/package -name 'testthat.Rout*' -exec cat '{}' \; || true
+        shell: bash
+
+      - name: Upload test results
+        if: failure()
+        uses: actions/upload-artifact@v3
+        with:
+          name: coverage-test-failures
+          path: ${{ runner.temp }}/package