From cbe2efd753138d49689cff4021094145fc56cbc8 Mon Sep 17 00:00:00 2001
From: Xavier Coulon <xcoulon@redhat.com>
Date: Mon, 18 Apr 2022 17:13:33 +0200
Subject: [PATCH] chore(bench): display bench stats as comment in PR

Fixes #992

Signed-off-by: Xavier Coulon <xcoulon@redhat.com>
---
 .github/workflows/ci-bench.yml | 27 ++++++++++++++++++---------
 make/bench.mk                  |  6 ++++--
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/.github/workflows/ci-bench.yml b/.github/workflows/ci-bench.yml
index 109eb3d9..ac827d68 100644
--- a/.github/workflows/ci-bench.yml
+++ b/.github/workflows/ci-bench.yml
@@ -1,11 +1,6 @@
-name: ci-build
+name: ci-bench
 on:
-  push:
-    branches:
-      - master
-    tags-ignore:
-      - '*.*'
-  pull_request:
+  pull_request_target:
     branches:
       - master
 
@@ -14,7 +9,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        go-version: [1.16.x,1.17.x]
+        go-version: [1.17.x]
         os: [ubuntu-latest]
     name: Benchstat with Go ${{ matrix.go-version }}
 
@@ -38,11 +33,25 @@ jobs:
           ${{ runner.os }}-go-
 
     - name: Verify parser
-      if: runner.os == 'Linux'
       run: |
         make verify-parser
 
     - name: Bench and Diff
+      id: bench-diff
       run: |
         go install golang.org/x/perf/cmd/benchstat@latest
         make bench-diff
+        echo "::set-output name=summary::$(make print-bench-diff)"
+
+    - name: Comment Benchmark Diffs
+        uses: marocchino/sticky-pull-request-comment@v2
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          header: bench
+          message: |
+            ### Benchmark Diffs
+            <details><summary>Benchmark diffs</summary>
+            ```
+            ${{ steps.bench-diff.outputs.summary }}
+            ```
+            </details>
diff --git a/make/bench.mk b/make/bench.mk
index a71fd7a8..143e6dc2 100644
--- a/make/bench.mk
+++ b/make/bench.mk
@@ -33,13 +33,15 @@ bench-diff: clean generate-optimized check-git-status
 		| tee $(REPORTS_DIR)/v0.7.0.bench
 	@echo "generated $(REPORTS_DIR)/v0.7.0.bench"
 	@git checkout $(GIT_BRANCH_NAME)
-	@echo ""
 	@echo "Comparing with 'master' branch"
 	@$(GOPATH)/bin/benchstat $(REPORTS_DIR)/$(GIT_BRANCH_NAME)-$(GIT_COMMIT_ID_SHORT).bench $(REPORTS_DIR)/master.bench
 	@echo ""
 	@echo "Comparing with 'v0.7.0' tag"
-	@$(GOPATH)/bin/benchstat $(REPORTS_DIR)/$(GIT_BRANCH_NAME)-$(GIT_COMMIT_ID_SHORT).bench $(REPORTS_DIR)/v0.7.0.bench
+	@$(GOPATH)/bin/benchstat $(REPORTS_DIR)/$(GIT_BRANCH_NAME)-$(GIT_COMMIT_ID_SHORT).bench $(REPORTS_DIR)/v0.7.0.bench | tee $(REPORTS_DIR)/diffs.txt
 
+print-bench-diff:
+	@cat $(REPORTS_DIR)/diffs.txt
+	
 check-git-status:
 ifneq ("$(shell git status --porcelain)","")
 	@echo "Repository contains uncommitted changes:"