From 9bda4eb999bf47a90e61b7d21c74e81f553bd5c8 Mon Sep 17 00:00:00 2001
From: Yuval Shavit <dev@yuvalshavit.com>
Date: Sun, 9 Jun 2024 15:15:15 -0400
Subject: [PATCH] add code coverage

Push coverage (lines %) to a gist, which then backs a
https://shields.io badge.
---
 .github/workflows/coverage.yml             | 26 ++++++++++++++++++
 .github/workflows/rust.yml                 |  4 +--
 README.md                                  |  2 ++
 {.github/workflows => scripts}/cargo_to_gh |  3 ++-
 scripts/common.sh                          | 10 +++++++
 scripts/percent_to_color                   | 31 ++++++++++++++++++++++
 scripts/percent_to_shields_gist            | 22 +++++++++++++++
 7 files changed, 95 insertions(+), 3 deletions(-)
 create mode 100644 .github/workflows/coverage.yml
 create mode 100644 README.md
 rename {.github/workflows => scripts}/cargo_to_gh (94%)
 create mode 100644 scripts/common.sh
 create mode 100755 scripts/percent_to_color
 create mode 100755 scripts/percent_to_shields_gist

diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
new file mode 100644
index 0000000..ecd93c5
--- /dev/null
+++ b/.github/workflows/coverage.yml
@@ -0,0 +1,26 @@
+name: Coverage
+
+on:
+  push:
+    branches: [ "main" ]
+
+jobs:
+  coverage:
+    runs-on: ubuntu-latest
+    environment: Code Coverage Badge
+    env:
+      CARGO_TERM_COLOR: always
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install cargo-llvm-cov
+        uses: taiki-e/install-action@cargo-llvm-cov
+      - name: Generate code coverage
+        run: |
+          percent_coverage="$(cargo llvm-cov --json | jq '.data[].totals.lines.percent')"
+          printf '::notice title=Coverage (lines %%)::%s' "$percent_coverage"
+          echo "LINES_PERCENT=$percent_coverage" >> "$GITHUB_ENV"
+      - name: Upload to gist
+        run: ./scripts/percent_to_shields_gist coverage "$LINES_PERCENT"
+        env:
+          GIST_URL: ${{ vars.GIST_URL }}
+          GH_TOKEN: ${{ secrets.API_TOKEN }}
diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index cff28d7..ffa0e69 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -15,7 +15,7 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     - name: cargo build
-      run:  .github/workflows/cargo_to_gh rustc --message-format json -- -Awarnings
+      run: scripts/cargo_to_gh rustc --message-format json -- -Awarnings
 
   check:
     runs-on: ubuntu-latest
@@ -23,7 +23,7 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     - name: cargo check
-      run: .github/workflows/cargo_to_gh check
+      run: scripts/cargo_to_gh check
 
   test:
     runs-on: ubuntu-latest
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..b261212
--- /dev/null
+++ b/README.md
@@ -0,0 +1,2 @@
+![Code Coverage](https://img.shields.io/endpoint?url=https%3A%2F%2Fgist.githubusercontent.com%2Fyshavit%2F53901a0115b596e015a891c41fb0f256%2Fraw%2Fmdq-coverage.json)
+
diff --git a/.github/workflows/cargo_to_gh b/scripts/cargo_to_gh
similarity index 94%
rename from .github/workflows/cargo_to_gh
rename to scripts/cargo_to_gh
index 4971e97..2261dda 100755
--- a/.github/workflows/cargo_to_gh
+++ b/scripts/cargo_to_gh
@@ -1,8 +1,9 @@
 #!/bin/bash
 
+source scripts/common.sh || exit 1
+
 json_opts=()
 if ! echo "$*" | grep -q -- '--message-format json' ; then
-  echo "NO: $*"
   json_opts=(--message-format json)
 fi
 
diff --git a/scripts/common.sh b/scripts/common.sh
new file mode 100644
index 0000000..693a821
--- /dev/null
+++ b/scripts/common.sh
@@ -0,0 +1,10 @@
+set -euo pipefail
+
+function msg() {
+  echo >&2 "$@"
+}
+
+function err() {
+  msg "$@"
+  exit 1
+}
diff --git a/scripts/percent_to_color b/scripts/percent_to_color
new file mode 100755
index 0000000..f8f3360
--- /dev/null
+++ b/scripts/percent_to_color
@@ -0,0 +1,31 @@
+#!/bin/bash
+
+source scripts/common.sh || exit 1
+
+if [ $# -ne 1 ]; then
+  err 'require exactly one argument'
+fi
+percent="$1"
+
+percent_0_to_5="$(printf 'scale=0; %s / 20\n' "$percent" | bc)"
+
+case "$percent_0_to_5" in
+  0) # 0 - 19%
+    echo darkred
+    ;;
+  1) # 20 - 39%
+    echo crimson
+    ;;
+  2) # 40 - 59%
+    echo orangered
+    ;;
+  3) # 60 - 79%
+    echo yellowgreen
+    ;;
+  4 | 5)
+    echo forestgreen 
+    ;;
+  *)
+    err 'invalid percent'
+    ;;
+esac
diff --git a/scripts/percent_to_shields_gist b/scripts/percent_to_shields_gist
new file mode 100755
index 0000000..44bebf1
--- /dev/null
+++ b/scripts/percent_to_shields_gist
@@ -0,0 +1,22 @@
+#!/bin/bash
+
+source scripts/common.sh || exit 1
+
+if [ -z "${GIST_URL:-}" ]; then
+  err "no GIST_URL env set"
+fi
+if [ $# -ne 2 ]; then
+  err 'requires exactly two arguments'
+fi
+label="$1"
+percent="$2"
+
+color="$(scripts/percent_to_color "$percent")"
+
+json_text="$(echo '{}' | 
+  jq -c '{schemaVersion: 1, label: $badge_label, color: $color, message: $percent}' \
+  --arg badge_label "$label" --arg color "$color" --arg percent "$(printf '%.1f%%' "$percent")" )"
+
+gh gist edit "$GIST_URL" <(echo "$json_text")
+
+