add CI github action

.github/workflows/ci.yml

@@ -0,0 +1,41 @@
+name: CI
+
+on:
+  pull_request:
+    branches:
+      - main
+  push:
+    branches:
+      - main
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+
+      - name: Install golangci-lint
+        run: |
+          curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.61.0
+          echo "$(go env GOPATH)/bin" >> $GITHUB_PATH
+
+      - name: Install gofumpt
+        run: go install mvdan.cc/gofumpt@v0.7.0
+
+      - name: Install dependencies
+        run: make deps || exit 1
+
+      - name: Lint
+        run: make lint || exit 1
+
+      - name: Check format
+        run: make format || exit 1
+
+      - name: Run tests
+        run: make test || exit 1

.golangci.yml

@@ -0,0 +1 @@
+run: {}

Makefile

@@ -0,0 +1,51 @@
+.DEFAULT_GOAL = check
+.PHONY: FORCE
+
+CC = /usr/local/musl/bin/musl-gcc
+GOFLAGS = -ldflags '-linkmode external -extldflags "-static"'
+OUTDIR = bin
+TESTGEN_BINARY = $(OUTDIR)/testgen
+
+build-testgen: $(TESTGEN_BINARY)
+.PHONY: build-testgen
+
+clean:
+	rm -f $(TESTGEN_BINARY)
+.PHONY: clean
+
+format:
+	gofumpt -l .
+	@if gofumpt -l . | grep -q .; then \
+		exit 1; \
+	fi
+.PHONY: format
+
+format-fix:
+	gofumpt -w .
+.PHONY: format-fix
+
+lint:
+	golangci-lint run --config .golangci.yml
+.PHONY: lint
+
+lint-fix:
+	golangci-lint run --fix --config .golangci.yml
+.PHONY: lint-fix
+
+test:
+	go test -v -p=4 ./...
+.PHONY: test
+
+check: format lint test
+.PHONY: check
+
+$(TESTGEN_BINARY): FORCE
+	@mkdir -p $(OUTDIR)
+	CC=$(CC) go build $(GOFLAGS) -o $@ ./cmd/testgen/main.go
+
+deps: FORCE
+	go mod tidy
+	go mod verify
+
+all: clean deps
+.PHONY: all

cmd/testgen/main.go

@@ -1,3 +1,5 @@
+//go:build linux
+
 package main
 
 import (

internal/testgen/cgetopt.go

@@ -179,6 +179,10 @@ func cGetOpt(cArgc C.int, cArgv []*C.char, optstring string, longoptstring strin
 	name := parseName(cLongoptions, char, optopt, flag)
 	mutArgs := copyCArgv(cArgc, cArgv)
 
+	if err == "-1" {
+		optarg = ""
+	}
+
 	if (err == "?" || err == ":") && (char == "" && name == "") {
 		val := strings.TrimPrefix(curr_arg, "-")
 		val = strings.TrimPrefix(val, "-")