Put everything in the same file

.github/workflows/pydoctor_primer.yaml

@@ -81,3 +81,88 @@ jobs:
         with:
           name: pydoctor_primer_diffs
           path: pr_number.txt
+
+  comment:
+    needs: [pydoctor_primer]
+    name: Comment PR from pydoctor_primer
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Download diffs
+        uses: actions/github-script@v6
+        with:
+          script: |
+            const fs = require('fs');
+            const artifacts = await github.rest.actions.listWorkflowRunArtifacts({
+               owner: context.repo.owner,
+               repo: context.repo.repo,
+               run_id: ${{ github.event.workflow_run.id }},
+            });
+            const [matchArtifact] = artifacts.data.artifacts.filter((artifact) =>
+              artifact.name == "pydoctor_primer_diffs");
+
+            const download = await github.rest.actions.downloadArtifact({
+               owner: context.repo.owner,
+               repo: context.repo.repo,
+               artifact_id: matchArtifact.id,
+               archive_format: "zip",
+            });
+            fs.writeFileSync("diff.zip", Buffer.from(download.data));
+
+      - run: unzip diff.zip
+      - run: |
+          cat diff_*.txt | tee fulldiff.txt
+
+      - name: Post comment
+        id: post-comment
+        uses: actions/github-script@v6
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const MAX_CHARACTERS = 30000
+            const MAX_CHARACTERS_PER_PROJECT = MAX_CHARACTERS / 3
+
+            const fs = require('fs')
+            let data = fs.readFileSync('fulldiff.txt', { encoding: 'utf8' })
+
+            function truncateIfNeeded(original, maxLength) {
+              if (original.length <= maxLength) {
+                return original
+              }
+              let truncated = original.substring(0, maxLength)
+              // further, remove last line that might be truncated
+              truncated = truncated.substring(0, truncated.lastIndexOf('\n'))
+              let lines_truncated = original.split('\n').length - truncated.split('\n').length
+              return `${truncated}\n\n... (truncated ${lines_truncated} lines) ...`
+            }
+
+            const projects = data.split('\n\n')
+            // don't let one project dominate
+            data = projects.map(project => truncateIfNeeded(project, MAX_CHARACTERS_PER_PROJECT)).join('\n\n')
+            // posting comment fails if too long, so truncate
+            data = truncateIfNeeded(data, MAX_CHARACTERS)
+
+            console.log("Diff from pydoctor_primer:")
+            console.log(data)
+
+            let body
+            if (data.trim()) {
+              body = 'Diff from [pydoctor_primer](https://github.com/tristanlatr/pydoctor_primer), showing the effect of this PR on open source code:\n```diff\n' + data + '```'
+            } else {
+              body = "According to [pydoctor_primer](https://github.com/tristanlatr/pydoctor_primer), this change doesn't affect type check results on a corpus of open source code. ✅"
+            }
+            const prNumber = parseInt(fs.readFileSync("pr_number.txt", { encoding: "utf8" }))
+            await github.rest.issues.createComment({
+              issue_number: prNumber,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              body
+            })
+            return prNumber
+
+      - name: Hide old comments
+        uses: kanga333/[email protected]
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          leave_visible: 1
+          issue_number: ${{ steps.post-comment.outputs.result }}