Add loading yaml label template files (#22976) (#23232)

Backport #22976

Extract from #11669 and enhancement to #22585 to support exclusive
scoped labels in label templates

* Move label template functionality to label module
* Fix handling of color codes
* Add Advanced label template

Co-authored-by: Lauris BH <lauris@nix.lv>

modules/label/parser_test.go

@@ -0,0 +1,72 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package label
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestYamlParser(t *testing.T) {
+	data := []byte(`labels:
+  - name: priority/low
+    exclusive: true
+    color: "#0000ee"
+    description: "Low priority"
+  - name: priority/medium
+    exclusive: true
+    color: "0e0"
+    description: "Medium priority"
+  - name: priority/high
+    exclusive: true
+    color: "#ee0000"
+    description: "High priority"
+  - name: type/bug
+    color: "#f00"
+    description: "Bug"`)
+
+	labels, err := parseYamlFormat("test", data)
+	require.NoError(t, err)
+	require.Len(t, labels, 4)
+	assert.Equal(t, "priority/low", labels[0].Name)
+	assert.True(t, labels[0].Exclusive)
+	assert.Equal(t, "#0000ee", labels[0].Color)
+	assert.Equal(t, "Low priority", labels[0].Description)
+	assert.Equal(t, "priority/medium", labels[1].Name)
+	assert.True(t, labels[1].Exclusive)
+	assert.Equal(t, "#00ee00", labels[1].Color)
+	assert.Equal(t, "Medium priority", labels[1].Description)
+	assert.Equal(t, "priority/high", labels[2].Name)
+	assert.True(t, labels[2].Exclusive)
+	assert.Equal(t, "#ee0000", labels[2].Color)
+	assert.Equal(t, "High priority", labels[2].Description)
+	assert.Equal(t, "type/bug", labels[3].Name)
+	assert.False(t, labels[3].Exclusive)
+	assert.Equal(t, "#ff0000", labels[3].Color)
+	assert.Equal(t, "Bug", labels[3].Description)
+}
+
+func TestLegacyParser(t *testing.T) {
+	data := []byte(`#ee0701 bug   ;   Something is not working
+#cccccc   duplicate ; This issue or pull request already exists
+#84b6eb enhancement`)
+
+	labels, err := parseLegacyFormat("test", data)
+	require.NoError(t, err)
+	require.Len(t, labels, 3)
+	assert.Equal(t, "bug", labels[0].Name)
+	assert.False(t, labels[0].Exclusive)
+	assert.Equal(t, "#ee0701", labels[0].Color)
+	assert.Equal(t, "Something is not working", labels[0].Description)
+	assert.Equal(t, "duplicate", labels[1].Name)
+	assert.False(t, labels[1].Exclusive)
+	assert.Equal(t, "#cccccc", labels[1].Color)
+	assert.Equal(t, "This issue or pull request already exists", labels[1].Description)
+	assert.Equal(t, "enhancement", labels[2].Name)
+	assert.False(t, labels[2].Exclusive)
+	assert.Equal(t, "#84b6eb", labels[2].Color)
+	assert.Empty(t, labels[2].Description)
+}