Add KDL parser (#266)

README.md

@@ -45,7 +45,7 @@ go get -u github.com/knadh/koanf/parsers/toml
 - [Reading raw bytes](#reading-raw-bytes)
 - [Reading from maps and structs](#reading-from-nested-maps)
 - [Unmarshalling and marshalling](#unmarshalling-and-marshalling)
-- [Order of merge and key case senstivity](#order-of-merge-and-key-case-sensitivity)
+- [Order of merge and key case sensitivity](#order-of-merge-and-key-case-sensitivity)
 - [Custom Providers and Parsers](#custom-providers-and-parsers)
 - [Custom merge strategies](#custom-merge-strategies)
 - [List of installable Providers and Parsers](#api)

parsers/kdl/go.mod

@@ -0,0 +1,13 @@
+module github.com/knadh/koanf/parsers/kdl
+
+go 1.18
+
+require (
+	github.com/pmezard/go-difflib v1.0.0 // i	github.com/sblinch/kdl-go v0.0.0-20231112203113-9fa9a505b79a // indirect
+	github.com/stretchr/testify v1.8.1
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/sblinch/kdl-go v0.0.0-20231112203113-9fa9a505b79a // indirect
+)

parsers/kdl/go.sum

@@ -0,0 +1,19 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sblinch/kdl-go v0.0.0-20231112203113-9fa9a505b79a h1:q2ywS3Q4C8vJKm0gBmUmub0yyLs6VAYivOKAvfhurJ4=
+github.com/sblinch/kdl-go v0.0.0-20231112203113-9fa9a505b79a/go.mod h1:b3oNGuAKOQzhsCKmuLc/urEOPzgHj6fB8vl8bwTBh28=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
+github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

parsers/kdl/kdl.go

@@ -0,0 +1,26 @@
+// Package kdl implements a koanf.Parser that parses KDL bytes as conf maps.
+package kdl
+
+import (
+	kdl "github.com/sblinch/kdl-go"
+)
+
+// KDL implements a KDL parser.
+type KDL struct{}
+
+// Parser returns a KDL Parser.
+func Parser() *KDL {
+	return &KDL{}
+}
+
+// Unmarshal parses the given KDL bytes.
+func (p *KDL) Unmarshal(b []byte) (map[string]interface{}, error) {
+	var o map[string]interface{}
+	err := kdl.Unmarshal(b, &o)
+	return o, err
+}
+
+// Marshal marshals the given config map to KDL bytes.
+func (p *KDL) Marshal(o map[string]interface{}) ([]byte, error) {
+	return kdl.Marshal(o)
+}

parsers/kdl/kdl_test.go

@@ -0,0 +1,189 @@
+package kdl
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestKDL_Unmarshal(t *testing.T) {
+	testCases := []struct {
+		name   string
+		input  []byte
+		keys   []string
+		values []interface{}
+		isErr  bool
+	}{
+		{
+			name:  "Empty KDL",
+			input: []byte(``),
+		},
+		{
+			name:   "Valid KDL",
+			input:  []byte(`key "val" ; name "test" ; number 2.0`),
+			keys:   []string{"key", "name", "number"},
+			values: []interface{}{"val", "test", 2.0},
+		},
+		{
+			name:  "Invalid KDL - syntax error",
+			input: []byte(`node1 key="val`),
+			isErr: true,
+		},
+		{
+			name: "Complex KDL - Different types",
+			input: []byte(`
+				array 1.0 2.0 3.0
+				boolean true
+				color "gold"
+				"null" null
+				number 123
+				object a="b" c="d" e=2.7 f=true
+				string "Hello World"
+			`),
+			keys: []string{"array", "boolean", "color", "null", "number", "object", "string"},
+			values: []interface{}{[]interface{}{1.0, 2.0, 3.0},
+				true,
+				"gold",
+				nil,
+				int64(123),
+				map[string]interface{}{"a": "b", "c": "d", "e": 2.7, "f": true},
+				"Hello World"},
+		},
+		{
+			name:  "Invalid KDL - missing value",
+			input: []byte(`node1 boolean=`),
+			isErr: true,
+		},
+		{
+			name: "Complex KDL - Nested map",
+			input: []byte(`key "value"
+					"1" "skipped"
+					map key="skipped" key="value"
+					nested_map {
+						map key="value" 17 {
+							list "item1" "item2" "item3"
+							mixup "y"=1 2 3 4
+							first "first"=1 2 3 4
+							child "test"=1 2 3 4 { "y" 5 ; "d" 6 ; }
+						}
+					}
+				`),
+			keys: []string{"key", "1", "map", "nested_map"},
+			values: []interface{}{
+				"value",
+				"skipped",
+				map[string]interface{}{
+					"key": "value",
+				},
+				map[string]interface{}{
+					"map": map[string]interface{}{
+						"0":   int64(17),
+						"key": "value",
+						"list": []interface{}{
+							"item1",
+							"item2",
+							"item3",
+						},
+						"mixup": map[string]interface{}{
+							"y": int64(1),
+							"0": int64(2),
+							"1": int64(3),
+							"2": int64(4),
+						},
+						"first": map[string]interface{}{
+							"first": int64(1),
+							"0":     int64(2),
+							"1":     int64(3),
+							"2":     int64(4),
+						},
+						"child": map[string]interface{}{
+							"test": int64(1),
+							"0":    int64(2),
+							"1":    int64(3),
+							"2":    int64(4),
+							"y":    int64(5),
+							"d":    int64(6),
+						},
+					},
+				},
+			},
+		},
+	}
+
+	k := Parser() // Assuming Parser() is implemented for KDL
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			out, err := k.Unmarshal(tc.input)
+			if tc.isErr {
+				assert.NotNil(t, err)
+			} else {
+				assert.Nil(t, err)
+				for i, k := range tc.keys {
+					v := out[k]
+					assert.Equal(t, tc.values[i], v)
+				}
+			}
+		})
+	}
+}
+
+func TestKDL_Marshal(t *testing.T) {
+	testCases := []struct {
+		name              string
+		input             map[string]interface{}
+		stringifiedOutput string
+		isErr             bool
+	}{
+		{
+			name:              "Empty KDL",
+			input:             map[string]interface{}{},
+			stringifiedOutput: ``,
+		},
+		{
+			name: "Valid KDL",
+			input: map[string]interface{}{
+				"key":    "val",
+				"name":   "test",
+				"number": 2.0,
+			},
+			stringifiedOutput: `key "val"
+name "test"
+number 2.0
+`,
+		},
+		{
+			name: "Complex KDL - Different types",
+			input: map[string]interface{}{
+				"null":    nil,
+				"boolean": true,
+				"color":   "gold",
+				"number":  int64(123),
+				"string":  "Hello World",
+				// "array":   []interface{}{1, 2, 3, 4, 5}, // https://github.com/sblinch/kdl-go/issues/3
+				"object": map[string]interface{}{"a": "b", "c": "d"},
+			},
+			stringifiedOutput: `boolean true
+color "gold"
+number 123
+string "Hello World"
+object a="b" c="d"
+null null
+`,
+		},
+	}
+
+	k := Parser() // Assuming Parser() is implemented for KDL
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			out, err := k.Marshal(tc.input)
+			if tc.isErr {
+				assert.NotNil(t, err)
+			} else {
+				assert.Nil(t, err)
+				assert.Equal(t, tc.stringifiedOutput, string(out))
+			}
+		})
+	}
+}