feat: add incremental coverage basic support

.gitignore

@@ -1,4 +1,4 @@
 .vscode
-cover.out
+*.out
 cover.txt
 cover.html

action.yaml

@@ -30,40 +30,51 @@ runs:
         path: go-cover
         token: ${{ inputs.token }}
 
+    - id : 'normalize-path'
+      name: Normalize Input Path
+      uses: actions/github-script@v7
+      with:
+        result-encoding: string
+        script: |
+          const script = require(`${process.env.GITHUB_ACTION_PATH}/src/normalize-path.js`)
+          return script('${{ inputs.path }}')
+
     - name: Checkout Coverage Branch
       shell: bash
       run: |
         export INPUTS_BRANCH="${{ inputs.branch }}"
+        export INPUTS_PATH="${{ steps.normalize-path.outputs.result }}"
         ${GITHUB_ACTION_PATH}/scripts/pull.sh
 
     - name: Push Coverage
       shell: bash
       run: |
         export REVISION="${{ github.event.pull_request.head.sha || github.sha }}"
-        export INPUTS_PATH="${{ inputs.path }}"
+        export INPUTS_PATH="${{ steps.normalize-path.outputs.result }}"
         export INPUTS_BRANCH="${{ inputs.branch }}"
         export REF_NAME="${{ github.ref_name }}"
         ${GITHUB_ACTION_PATH}/scripts/push.sh
 
     - name: Post Code Coverage Comment
       if: ${{ github.event_name == 'pull_request' }}
-      uses: actions/github-script@v6
+      uses: actions/github-script@v7
       with:
         github-token: ${{ inputs.token }}
         script: |
           const script = require(`${process.env.GITHUB_ACTION_PATH}/src/update-comment.js`)
           const revision = '${{ github.event.pull_request.head.sha || github.sha }}'
-          const path = '${{ inputs.path }}'
           const threshold = parseFloat('${{ inputs.threshold }}', 10)
+          const path = '${{ steps.normalize-path.outputs.result }}'
           await script({ context, github, path, revision, threshold })
 
     - name: Check Coverage Threshold
       if: ${{ github.event_name == 'pull_request' }}
-      uses: actions/github-script@v6
+      uses: actions/github-script@v7
       with:
         github-token: ${{ inputs.token }}
         script: |
           const script = require(`${process.env.GITHUB_ACTION_PATH}/src/check-threshold.js`)
           const revision = '${{ github.event.pull_request.head.sha || github.sha }}'
           const threshold = parseFloat('${{ inputs.threshold }}', 10)
-          await script({ threshold, revision })
+          const path = '${{ steps.normalize-path.outputs.result }}'
+          await script({ threshold, path, revision })

assets/index.html

@@ -58,7 +58,7 @@
       async function loadContent() {
         const spinner = document.getElementById("spinner");
         const hash = getHashFromQueryString();
-        const fileUrl = `${hash}.html`;
+        const fileUrl = `revisions/${hash}.html`;
 
         spinner.style.display = "block";
 

assets/nord.css

@@ -41,7 +41,7 @@
 
 body {
   background: var(--nord0) !important;
-  color: var(--nord4) !important;
+  color: var(--nord3) !important;
 }
 
 #topbar {

go-test-app-01/main.go

@@ -5,12 +5,16 @@ import (
 	"math/rand"
 )
 
+const side = "right"
+
 func main() {
 	if tossCoin() == "heads" {
 		fmt.Println("Heads")
 	} else {
 		fmt.Println("Tails")
 	}
+
+	fmt.Println("Maybe:", maybe())
 }
 
 func tossCoin() string {
@@ -20,3 +24,11 @@ func tossCoin() string {
 		return "tails"
 	}
 }
+
+func maybe() bool {
+	if side == "right" {
+		return true
+	} else {
+		return false
+	}
+}

scripts/pull.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-set -eo pipefail
+set -xeo pipefail
 
 cd go-cover
 git fetch origin
@@ -13,4 +13,8 @@ else
   git checkout --orphan "${INPUTS_BRANCH}"
   rm .git/index
   git clean -fdx
+  mkdir -p "./${INPUTS_PATH}/head"
+  touch "./${INPUTS_PATH}/head/head.html"
+  touch "./${INPUTS_PATH}/head/head.txt"
+  echo "mode: set" > "./${INPUTS_PATH}/head/head.out"
 fi

scripts/push.sh

@@ -1,30 +1,53 @@
 #!/bin/bash
 
-set -eo pipefail
+set -xeo pipefail
+
+# create cover directory
+
+cover_dir="${GITHUB_WORKSPACE}/go-cover/./${INPUTS_PATH}"
+mkdir -p "${cover_dir}/revisions"
+mkdir -p "${cover_dir}/head"
 
-# generate coverage files
 cd "${INPUTS_PATH}"
-go tool cover -html=cover.out -o "${GITHUB_WORKSPACE}/go-cover/${REVISION}.html"
-go tool cover -func=cover.out -o "${GITHUB_WORKSPACE}/go-cover/${REVISION}.txt"
-cp cover.out                     "${GITHUB_WORKSPACE}/go-cover/${REVISION}.out"
 
-# if we are on the main branch, copy files to main.*
-if [ "${REF_NAME}" = "main" ]; then
-  cp "${GITHUB_WORKSPACE}/go-cover/${REVISION}.html" "${GITHUB_WORKSPACE}/go-cover/main.html"
-  cp "${GITHUB_WORKSPACE}/go-cover/${REVISION}.txt"  "${GITHUB_WORKSPACE}/go-cover/main.txt"
-  cp "${GITHUB_WORKSPACE}/go-cover/${REVISION}.out"  "${GITHUB_WORKSPACE}/go-cover/main.out"
-fi
+# generate coverage files
+
+go tool cover -html=cover.out -o "${cover_dir}/revisions/${REVISION}.html"
+go tool cover -func=cover.out -o "${cover_dir}/revisions/${REVISION}.txt"
+cp cover.out                     "${cover_dir}/revisions/${REVISION}.out"
+
+# generate incremental coverage files
 
-cd "${GITHUB_WORKSPACE}/go-cover"
+echo "mode: set" > incremental.out
+# grep exits with 1 if no lines are found, so we need to ignore that
+grep -F -v -x -f "${GITHUB_WORKSPACE}/go-cover/head/head.out" cover.out >> incremental.out || true
+go tool cover -html=incremental.out -o "${cover_dir}/revisions/${REVISION}-inc.html"
+go tool cover -func=incremental.out -o "${cover_dir}/revisions/${REVISION}-inc.txt"
+cp incremental.out                     "${cover_dir}/revisions/${REVISION}-inc.out"
+
+cd "${cover_dir}"
 
 # beautify html
-ex -sc '%s/<style>/<style>@import url("nord.css");/'             -c 'x' "${REVISION}.html"
-ex -sc '%s/<\/script>/<\/script><script src="ln.js"><\/script>/' -c 'x' "${REVISION}.html"
+
+for file in "revisions/${REVISION}.html" "revisions/${REVISION}-inc.html"; do
+  ex -sc '%s/<style>/<style>@import url("..\/nord.css");/'             -c 'x' "${file}"
+  ex -sc '%s/<\/script>/<\/script><script src="..\/index.js"><\/script>/' -c 'x' "${file}"
+done
+
+# if we are on the main branch, copy files to main.*
+
+if [ "${REF_NAME}" = "main" ]; then
+  cp "revisions/${REVISION}.html" "${cover_dir}/head/head.html"
+  cp "revisions/${REVISION}.txt"  "${cover_dir}/head/head.txt"
+  cp "revisions/${REVISION}.out"  "${cover_dir}/head/head.out"
+fi
 
 # copy assets
-cp "${GITHUB_ACTION_PATH}"/assets/* .
+
+cp "${GITHUB_ACTION_PATH}"/assets/* "${cover_dir}"
 
 # push to branch
+
 git add .
 git config user.email "go-coverage-action@github.com"
 git config user.name "go-coverage-action"

src/check-threshold.js

@@ -1,7 +1,10 @@
 const fs = require('fs')
+const normalizePath = require('./normalize-path')
 
-const checkThreshold = module.exports = async ({ threshold, revision }) => {
-  const coverageText = fs.readFileSync(`go-cover/${revision}.txt`, 'utf8').split('\n').slice(0, -1)
+const checkThreshold = module.exports = async ({ threshold, path, revision }) => {
+  path = normalizePath(path)
+
+  const coverageText = fs.readFileSync(`go-cover/${path}/revisions/${revision}.txt`, 'utf8').split('\n').slice(0, -1)
   const coverageTextSummary = coverageText[coverageText.length-1].split('\t').pop()
 
   const coverage = parseFloat(coverageTextSummary.replace('%', ''), 10)

src/normalize-path.js

@@ -0,0 +1,62 @@
+const path = require('path')
+
+const normalizePath = module.exports = (dir) => {
+  dir = path.normalize(dir)
+
+  if (dir === '/' || dir === './' || dir === '.') {
+    return ''
+  }
+
+  if (dir.startsWith('./')) {
+    dir = dir.substring(2)
+  }
+
+  if (dir.startsWith('/')) {
+    dir = dir.substring(1)
+  }
+
+  if (dir.endsWith('/')) {
+    dir = dir.substring(0, dir.length - 1)
+  }
+
+  return dir
+}
+
+const test = async () => {
+  let pass = true
+
+  const tests = [
+    { input: '/', expected: '' },
+    { input: '/foo', expected: 'foo' },
+
+    { input: './', expected: '' },
+    { input: './foo', expected: 'foo' },
+    { input: './foo/', expected: 'foo' },
+    { input: './foo/bar', expected: 'foo/bar' },
+    { input: './foo/bar/', expected: 'foo/bar' },
+
+    { input: '', expected: '' },
+    { input: 'foo', expected: 'foo' },
+    { input: 'foo/', expected: 'foo' },
+    { input: 'foo/bar', expected: 'foo/bar' },
+    { input: 'foo/bar/', expected: 'foo/bar' },
+  ]
+
+  for (const { input, expected } of tests) {
+    const result = normalizePath(input)
+    if (result !== expected) {
+      console.error(`error("${input}"): expected "${expected}" but got "${result}"`)
+      pass = false
+    }
+  }
+
+  if (!pass) {
+    process.exit(1)
+  } else {
+    console.log('All tests passed')
+  }
+}
+
+if (require.main === module) {
+  test()
+}

src/update-comment.js

@@ -1,4 +1,6 @@
 const fs = require('fs')
+const normalizePath = require('./normalize-path')
+const join = require('path').join
 
 const updateCodeCoverageComment = module.exports = async ({ context, github, path, revision, threshold }) => {
   const comments = await github.rest.issues.listComments({
@@ -8,19 +10,22 @@ const updateCodeCoverageComment = module.exports = async ({ context, github, pat
     per_page: 100
   })
 
+  path = normalizePath(path)
+
   const coverageComment = comments.data.find((comment) => {
     return comment.body.startsWith(`<!-- coverage (${path})-->`)
   }) || {}
 
-  const coverageText = fs.readFileSync(`go-cover/${revision}.txt`, 'utf8').split('\n').slice(0, -1)
+  const coverageText = fs.readFileSync(join('go-cover', path, 'revisions', `${revision}.txt`), 'utf8').split('\n').slice(0, -1)
   const coverageTextSummary = coverageText[coverageText.length-1].split('\t').pop()
   const coverage = parseFloat(coverageTextSummary.replace('%', ''), 10)
   const coverageEmoji = coverage >= threshold ? '' : `<kbd>🔻 ${(coverage - threshold).toFixed(1)}%</kbd> `
-  const pathText = (path !== './' ? ` for <kbd>${path}/</kbd>` : '').replace('//', '/')
+  const pathText = (path !== '' ? ` for <kbd>${path}/</kbd>` : '')
+  const url = `https://${context.repo.owner}.github.io/${join(context.repo.repo, path)}?hash=${revision}`
 
   const commentBody = [
     `<!-- coverage (${path})-->`,
-    `##### ${coverageEmoji}<kbd>[🔗 Code Coverage Report](https://${context.repo.owner}.github.io/${context.repo.repo}/?hash=${revision})</kbd>${pathText} at <kbd>${revision}</kbd>`,
+    `##### ${coverageEmoji}<kbd>[🔗 Code Coverage Report](${url})</kbd>${pathText} at <kbd>${revision}</kbd>`,
     '```',
     `📔 Total: ${coverageTextSummary}`,
   ]