Add wildcard token to match all elements in an array

Useful for replace operations

Author: aeijdenberg

patch/pointer.go

@@ -52,6 +52,12 @@ func NewPointerFromString(str string) (Pointer, error) {
 			continue
 		}
 
+		// parse wildcard
+		if tok == "*" {
+			tokens = append(tokens, WildcardToken{})
+			continue
+		}
+
 		// parse as index
 		idx, err := strconv.Atoi(tok)
 		if err == nil {

patch/replace_op_test.go

@@ -8,6 +8,35 @@ import (
 )
 
 var _ = Describe("ReplaceOp.Apply", func() {
+	Describe("multiple replace", func() {
+		It("replaces many items", func() {
+			res, err := ReplaceOp{Path: MustNewPointerFromString("/instance_groups/*/vm_extensions?/-"), Value: "ex2"}.Apply(map[interface{}]interface{}{
+				"instance_groups": []interface{}{
+					map[interface{}]interface{}{
+						"name":          "foo",
+						"vm_extensions": []interface{}{"ex1"},
+					},
+					map[interface{}]interface{}{
+						"name": "bar",
+					},
+				},
+			})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res).To(Equal(map[interface{}]interface{}{
+				"instance_groups": []interface{}{
+					map[interface{}]interface{}{
+						"name":          "foo",
+						"vm_extensions": []interface{}{"ex1", "ex2"},
+					},
+					map[interface{}]interface{}{
+						"name":          "bar",
+						"vm_extensions": []interface{}{"ex2"},
+					},
+				},
+			}))
+		})
+	})
+
 	It("returns error if replacement value cloning fails", func() {
 		_, err := ReplaceOp{Path: MustNewPointerFromString(""), Value: func() {}}.Apply("a")
 		Expect(err).To(HaveOccurred())

patch/token_wildcard.go

@@ -0,0 +1,32 @@
+package patch
+
+import "errors"
+
+type WildcardToken struct{}
+
+func (t WildcardToken) String() string {
+	return "*"
+}
+
+func (t WildcardToken) processDescent(ctx *tokenContext) (interface{}, error) {
+	if ctx.IsLast() {
+		return nil, errors.New("wildcard can't be used for last element. Use - instead")
+	}
+	if ctx.Method != methodReplace && ctx.Method != methodRemove {
+		return nil, errors.New("operation using wildcard")
+	}
+
+	typedArray, ok := ctx.Node.([]interface{})
+	if !ok {
+		return nil, newOpArrayMismatchTypeErr(ctx.Tokens[:ctx.TokenIndex+1], ctx.Node)
+	}
+	for idx, e := range typedArray {
+		ctx.Node = e
+		ctx.Setter = func(newObj interface{}) { typedArray[idx] = newObj }
+		_, err := ctx.Descend()
+		if err != nil {
+			return nil, err
+		}
+	}
+	return nil, nil
+}