add cnf/json set() + tests pass

internal/cnf/json.go

@@ -2,6 +2,7 @@ package cnf
 
 import (
 	"encoding/json"
+	"fmt"
 	"io"
 	"strings"
 )
@@ -26,29 +27,100 @@ func (d *Json) Parse(_reader io.Reader) error {
 
 }
 
-// Get returns the value of a dot-separated path, and if it exists
-func (d *Json) Get(_path string) (string, bool) {
+// browse returns the target of a dot-separated path (as an interface{} chain where the last is the target if found)
+func (d *Json) browse(_path string) ([]interface{}, bool) {
 
 	// 1. extract path
 	path := strings.Split(_path, ".")
 
-	// 2. Iterate over path / nested fields
+	// 2. init output chain
 	current := d.data
+	chain := make([]interface{}, 0, len(path)+1)
+	chain = append(chain, current)
+
+	// 3. iterate over path / nested fields
 	for _, field := range path {
 		fmap, ok := current.(map[string]interface{})
 		if !ok { // incomplete path
-			return "", false
+			return chain, false
 		}
 
 		child, ok := fmap[field]
 		if !ok { // incomplete path
-			return "", false
+			return chain, false
 		}
 
 		current = child
+		chain = append(chain, current)
 	}
 
-	// 3. Only return if string value
-	value, ok := current.(string)
-	return value, ok
+	return chain, true
+}
+
+// Get returns the value of a dot-separated path, and if it exists
+func (d *Json) Get(_path string) (string, bool) {
+
+	// 1. browse path
+	chain, found := d.browse(_path)
+	if !found {
+		return "", false
+	}
+
+	// 2. return if string value
+	value, ok := chain[len(chain)-1].(string)
+	return value, ok
+
+}
+
+// Set the value of a dot-separated path, and creates it if not found
+func (d *Json) Set(_path, _value string) bool {
+
+	// 1. browse path + create it if does not exist
+	path := strings.Split(_path, ".")
+	chain, found := d.browse(_path)
+
+	// 2. if found -> set value
+	if found {
+		mapWrapper, ok := chain[len(chain)-2].(map[string]interface{})
+		if !ok { // impossible
+			return false
+		}
+		key := path[len(path)-1]
+		mapWrapper[key] = _value
+		return true
+	}
+
+	// 3. create path until the end to set value
+	root := make(map[string]interface{})
+	current := root
+
+	// create children until second to last
+	fmt.Printf("%d / %d\n", len(chain)-1, len(path))
+	for i, l := len(chain)-1, len(path)-1; i < l; i++ {
+		child := make(map[string]interface{})
+		fmt.Printf("add '%s'\n", path[i])
+		current[path[i]] = child
+		current = child
+	}
+
+	// set value
+	current[path[len(path)-1]] = _value
+
+	// replace whole object if empty
+	if len(chain) < 2 {
+		d.data = root
+		return true
+	}
+
+	// update last found object to add the value
+	wrapper, ok := chain[len(chain)-2].(map[string]interface{})
+	if !ok { // impossible
+		return false
+	}
+
+	key := path[len(chain)-2]
+	wrapper[key] = root
+
+	return true
+
 }

internal/cnf/json_test.go

@@ -5,7 +5,7 @@ import (
 	"testing"
 )
 
-func TestSimpleJson(t *testing.T) {
+func TestGet(t *testing.T) {
 
 	tests := []struct {
 		raw string
@@ -45,7 +45,7 @@ func TestSimpleJson(t *testing.T) {
 
 }
 
-func TestNotString(t *testing.T) {
+func TestGetNotString(t *testing.T) {
 
 	tests := []struct {
 		raw string
@@ -79,3 +79,100 @@ func TestNotString(t *testing.T) {
 	}
 
 }
+
+func TestSetPathExistsAndIsString(t *testing.T) {
+
+	tests := []struct {
+		raw   string
+		key   string
+		value string
+	}{
+		{`{ "key": "value" }`, "key", "newvalue"},
+		{`{ "ignore": "xxx", "key": "value" }`, "key", "newvalue"},
+		{`{ "parent": { "child": "value" } }`, "parent.child", "newvalue"},
+		{`{ "ignore": "xxx", "parent": { "child": "value" } }`, "parent.child", "newvalue"},
+	}
+
+	for _, test := range tests {
+
+		parser := new(Json)
+		reader := bytes.NewBufferString(test.raw)
+
+		// try to extract value
+		err := parser.Parse(reader)
+		if err != nil {
+			t.Errorf("parse error: %s", err)
+			continue
+		}
+
+		// update value
+		if !parser.Set(test.key, test.value) {
+			t.Errorf("cannot set '%s' to '%s'", test.key, test.value)
+			continue
+		}
+
+		// check new value
+		value, found := parser.Get(test.key)
+		if !found {
+			t.Errorf("expected a result, got none")
+			continue
+		}
+
+		// check value
+		if value != test.value {
+			t.Errorf("expected '%s' got '%s'", test.value, value)
+		}
+
+	}
+
+}
+
+func TestSetCreatePath(t *testing.T) {
+
+	tests := []struct {
+		raw   string
+		key   string
+		value string
+	}{
+		{`{ }`, "key", "newvalue"},
+		{`{ }`, "parent.child", "newvalue"},
+		{`{ }`, "parent.child.subchild", "newvalue"},
+
+		{`{ "ignore": "xxx" }`, "key", "newvalue"},
+		{`{ "parent": { } }`, "parent.child", "newvalue"},
+		{`{ "ignore": "xxx", "parent": { } }`, "parent.child", "newvalue"},
+	}
+
+	for i, test := range tests {
+
+		parser := new(Json)
+		reader := bytes.NewBufferString(test.raw)
+
+		// try to extract value
+		err := parser.Parse(reader)
+		if err != nil {
+			t.Errorf("[%d] parse error: %s", i, err)
+			continue
+		}
+
+		// update value
+		if !parser.Set(test.key, test.value) {
+			t.Errorf("[%d] cannot set '%s' to '%s'", i, test.key, test.value)
+			continue
+		}
+
+		// check new value
+		value, found := parser.Get(test.key)
+		if !found {
+			t.Errorf("[%d] expected a result, got none", i)
+			continue
+		}
+
+		// check value
+		if value != test.value {
+			t.Errorf("[%d] expected '%s' got '%s'", i, test.value, value)
+		}
+
+	}
+
+}