ci: check generated parser code before running unit tests

Check that the generated parser code is consistent with the input definition.

Remove the file before re-generating to make sure that missing goyacc is
not effecting the check.

Fixes: #7488

Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>

.github/workflows/ci.yml

@@ -143,6 +143,19 @@ jobs:
         with:
           parallelism: 12
           thread: ${{ matrix.thread }}
+  check_generated_parser:
+    name: Check generated parser
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633 # v4.1.2
+      - name: Install Go
+        uses: actions/setup-go@0c52d547c9bc32b1aa3301fd7a9cb496313a4491 # v5.0.0
+        with:
+          cache: false
+          go-version: 1.22.x
+      - name: Run goyacc and check for diff
+        run: make install-goyacc check-generated-parser
   golangci:
     name: golangci-lint
     runs-on: ubuntu-latest

Makefile

@@ -24,6 +24,7 @@ TSDB_BENCHMARK_DATASET ?= ./tsdb/testdata/20kseries.json
 TSDB_BENCHMARK_OUTPUT_DIR ?= ./benchout
 
 GOLANGCI_LINT_OPTS ?= --timeout 4m
+GOYACC_VERSION ?= v0.6.0
 
 include Makefile.common
 
@@ -78,24 +79,42 @@ assets-tarball: assets
 	@echo '>> packaging assets'
 	scripts/package_assets.sh
 
-# We only want to generate the parser when there's changes to the grammar.
 .PHONY: parser
 parser:
 	@echo ">> running goyacc to generate the .go file."
 ifeq (, $(shell command -v goyacc 2> /dev/null))
 	@echo "goyacc not installed so skipping"
-	@echo "To install: go install golang.org/x/tools/cmd/goyacc@v0.6.0"
+	@echo "To install: \"go install golang.org/x/tools/cmd/goyacc@$(GOYACC_VERSION)\" or run \"make install-goyacc\""
 else
-	goyacc -l -o promql/parser/generated_parser.y.go promql/parser/generated_parser.y
+	$(MAKE) promql/parser/generated_parser.y.go
 endif
 
+promql/parser/generated_parser.y.go: promql/parser/generated_parser.y
+	@echo ">> running goyacc to generate the .go file."
+	@goyacc -l -o promql/parser/generated_parser.y.go promql/parser/generated_parser.y
+
+.PHONY: clean-parser
+clean-parser:
+	@echo ">> cleaning generated parser"
+	@rm -f promql/parser/generated_parser.y.go
+
+.PHONY: check-generated-parser
+check-generated-parser: clean-parser promql/parser/generated_parser.y.go
+	@echo ">> checking generated parser"
+	@git diff --exit-code -- promql/parser/generated_parser.y.go || (echo "Generated parser is out of date. Please run 'make parser' and commit the changes." && false)
+
+.PHONY: install-goyacc
+install-goyacc:
+	@echo ">> installing goyacc $(GOYACC_VERSION)"
+	@go install golang.org/x/tools/cmd/goyacc@$(GOYACC_VERSION)
+
 .PHONY: test
 # If we only want to only test go code we have to change the test target
 # which is called by all.
 ifeq ($(GO_ONLY),1)
 test: common-test check-go-mod-version
 else
-test: common-test ui-build-module ui-test ui-lint check-go-mod-version
+test: check-generated-parser common-test ui-build-module ui-test ui-lint check-go-mod-version
 endif
 
 .PHONY: npm_licenses