diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
new file mode 100644
index 0000000..90598ab
--- /dev/null
+++ b/.github/workflows/tests.yaml
@@ -0,0 +1,44 @@
+name: "tests"
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  lint:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v3
+        with: { version: latest }
+
+  test:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Print system information
+        run: cat /proc/{meminfo,cpuinfo}
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+      - name: Install dependencies
+        run: go get .
+      - name: Build
+        run: go build -v ./...
+      - name: Test with the Go CLI
+        run: TEST_FORMAT=github-actions make test
+
diff --git a/.golangci.yml b/.golangci.yml
new file mode 100644
index 0000000..3c85559
--- /dev/null
+++ b/.golangci.yml
@@ -0,0 +1,18 @@
+run:
+  go: '1.22'
+linters:
+  enable:
+    - govet
+    - typecheck
+    - unused
+    - gofmt
+    - whitespace
+    - gosimple
+    - exportloopref
+    - nilerr
+    - goimports
+    - staticcheck
+    - ineffassign
+    - errcheck
+  disable:
+    - depguard
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..2fb8678
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,12 @@
+.PHONY: test lint
+
+TEST_FORMAT ?= standard-quiet
+LINT_FORMAT ?= colored-line-number
+
+all: test lint
+
+test:
+	go install gotest.tools/gotestsum@latest
+	gotestsum --format $(TEST_FORMAT) -- -tags=test ./...
+lint:
+	golangci-lint run --out-format $(LINT_FORMAT) --verbose
diff --git a/djot_parser/djot_ast.go b/djot_parser/djot_ast.go
index e5a1563..3bb71f7 100644
--- a/djot_parser/djot_ast.go
+++ b/djot_parser/djot_ast.go
@@ -262,7 +262,7 @@ type QuoteDirection int
 
 const (
 	OpenQuote  QuoteDirection = +1
-	CloseQuote                = -1
+	CloseQuote QuoteDirection = -1
 )
 
 func detectQuoteDirection(document []byte, position int) QuoteDirection {
diff --git a/djot_tokenizer/attributes.go b/djot_tokenizer/attributes.go
index 8bbc17e..fce8d3b 100644
--- a/djot_tokenizer/attributes.go
+++ b/djot_tokenizer/attributes.go
@@ -24,7 +24,6 @@ func MatchQuotedString(r tokenizer.TextReader, s tokenizer.ReaderState) ([]byte,
 		tokenizer.Assertf(ok, "MaskRepeat must match because minCount is zero")
 
 		value = append(value, r[start:next]...)
-		start = next
 		if endString, ok := r.Token(next, "\""); ok {
 			return value, endString, true
 		} else if escape, ok := r.Token(next, "\\"); ok {
diff --git a/tokenizer/line_tokenizer_test.go b/tokenizer/line_tokenizer_test.go
index 30f9f1b..53be67c 100644
--- a/tokenizer/line_tokenizer_test.go
+++ b/tokenizer/line_tokenizer_test.go
@@ -1,8 +1,9 @@
 package tokenizer
 
 import (
-	"github.com/stretchr/testify/require"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestLineTokenizer(t *testing.T) {