Fixed += operator (https://github.com/mikefarah/yq/issues/750)

go.sum

@@ -171,7 +171,6 @@ github.com/spf13/cast v1.3.0/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkU
 github.com/spf13/cobra v1.1.1 h1:KfztREH0tPxJJ+geloSLaAkaPkr4ki2Er5quFV1TDo4=
 github.com/spf13/cobra v1.1.1/go.mod h1:WnodtKOvamDL/PwE2M4iKs8aMDBZ5Q5klgD3qfVJQMI=
 github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
-github.com/spf13/pflag v1.0.3 h1:zPAT6CGy6wXeQ7NtTnaTerfKOsV6V6F8agHXFiazDkg=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
@@ -180,7 +179,6 @@ github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
-github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
@@ -257,7 +255,6 @@ golang.org/x/sys v0.0.0-20190507160741-ecd444e8653b/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20190606165138-5da285871e9c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190624142023-c5567b49c5d0/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae h1:/WDfKMnPU+m5M4xB+6x4kaepxRw6jWvR5iDRdvjHgy8=
 golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c h1:VwygUrnw9jn88c4u8GD3rZQbqrP/tgas88tPUbBxQrk=
 golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -270,7 +267,6 @@ golang.org/x/tools v0.0.0-20180221164845-07fd8470d635/go.mod h1:n7NCudcB/nEzxVGm
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190226205152-f727befe758c/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=
-golang.org/x/tools v0.0.0-20190311212946-11955173bddd h1:/e+gpKk9r3dJobndpTytxS2gOy6m5uvpg+ISQoEcusQ=
 golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 golang.org/x/tools v0.0.0-20190312151545-0bb0c0a6e846/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 golang.org/x/tools v0.0.0-20190312170243-e65039ee4138/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
@@ -283,7 +279,6 @@ golang.org/x/tools v0.0.0-20190628153133-6cdbf07be9d0/go.mod h1:/rFqwRUd4F7ZHNgw
 golang.org/x/tools v0.0.0-20190816200558-6889da9d5479/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20190911174233-4f2ddba30aff/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20191012152004-8de300cfc20a/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/tools v0.0.0-20191112195655-aa38f8e97acc h1:NCy3Ohtk6Iny5V/reW2Ktypo4zIpWBdRJ1uFMjBxdg8=
 golang.org/x/tools v0.0.0-20191112195655-aa38f8e97acc/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
@@ -310,7 +305,6 @@ google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZi
 google.golang.org/grpc v1.20.1/go.mod h1:10oTOabMzJvdu6/UiuZezV6QK5dSlG84ov/aaiqXj38=
 google.golang.org/grpc v1.21.1/go.mod h1:oYelfM1adQP15Ek0mdvEgi9Df8B9CZIaU1084ijfRaM=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
-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/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
@@ -321,10 +315,8 @@ gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473/go.mod h1:N1eN2tsCx
 gopkg.in/resty.v1 v1.12.0/go.mod h1:mDo4pnntr5jdWRML875a/NmxYqAlA73dVijT2AXvQQo=
 gopkg.in/yaml.v2 v2.0.0-20170812160011-eb3733d160e7/go.mod h1:JAlM8MvJe8wmxCU4Bli9HhUf9+ttbYbLASfIpnQbh74=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
 gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b h1:h8qDotaEPuJATrMmW04NCwg7v22aHH28wwpauUhK9Oo=

pkg/yqlib/doc/Add.md

@@ -101,7 +101,7 @@ will output
 - hello
 ```
 
-## Update array (append)
+## Append to array
 Given a sample.yml file of:
 ```yaml
 a:
@@ -127,6 +127,36 @@ b:
   - 4
 ```
 
+## Relative append
+Given a sample.yml file of:
+```yaml
+a:
+  a1:
+    b:
+      - cat
+  a2:
+    b:
+      - dog
+  a3: {}
+```
+then
+```bash
+yq eval '.a[].b += ["mouse"]' sample.yml
+```
+will output
+```yaml
+a:
+  a1:
+    b:
+      - cat
+      - mouse
+  a2:
+    b:
+      - dog
+      - mouse
+  a3: {b: [mouse]}
+```
+
 ## String concatenation
 Given a sample.yml file of:
 ```yaml
@@ -143,22 +173,6 @@ a: catmeow
 b: meow
 ```
 
-## Relative string concatenation
-Given a sample.yml file of:
-```yaml
-a: cat
-b: meow
-```
-then
-```bash
-yq eval '.a += .b' sample.yml
-```
-will output
-```yaml
-a: catmeow
-b: meow
-```
-
 ## Number addition - float
 If the lhs or rhs are floats then the expression will be calculated with floats.
 
@@ -195,18 +209,20 @@ a: 7
 b: 4
 ```
 
-## Increment number
+## Increment numbers
 Given a sample.yml file of:
 ```yaml
 a: 3
+b: 5
 ```
 then
 ```bash
-yq eval '.a += 1' sample.yml
+yq eval '.[] += 1' sample.yml
 ```
 will output
 ```yaml
 a: 4
+b: 6
 ```
 
 ## Add to null

pkg/yqlib/expression_processing_test.go

@@ -13,17 +13,17 @@ var pathTests = []struct {
 	expectedPostFix []interface{}
 }{
 	{
-		`[]|join(".")`, 
+		`[]|join(".")`,
 		append(make([]interface{}, 0), "[", "EMPTY", "]", "PIPE", "JOIN", "(", ". (string)", ")"),
-		append(make([]interface{}, 0), "EMPTY", "COLLECT", "SHORT_PIPE", ". (string)", "JOIN", "PIPE" ),
+		append(make([]interface{}, 0), "EMPTY", "COLLECT", "SHORT_PIPE", ". (string)", "JOIN", "PIPE"),
 	},
 	{
-		`{"cool": .b or .c}`, 
+		`{"cool": .b or .c}`,
 		append(make([]interface{}, 0), "{", "cool (string)", "CREATE_MAP", "b", "OR", "c", "}"),
 		append(make([]interface{}, 0), "cool (string)", "b", "c", "OR", "CREATE_MAP", "COLLECT_OBJECT", "SHORT_PIPE"),
 	},
 	{
-		`{"cool": []|join(".")}`, 
+		`{"cool": []|join(".")}`,
 		append(make([]interface{}, 0), "{", "cool (string)", "CREATE_MAP", "[", "EMPTY", "]", "PIPE", "JOIN", "(", ". (string)", ")", "}"),
 		append(make([]interface{}, 0), "cool (string)", "EMPTY", "COLLECT", "SHORT_PIPE", ". (string)", "JOIN", "PIPE", "CREATE_MAP", "COLLECT_OBJECT", "SHORT_PIPE"),
 	},

pkg/yqlib/operator_add.go

@@ -16,9 +16,9 @@ func createAddOp(lhs *ExpressionNode, rhs *ExpressionNode) *ExpressionNode {
 
 func addAssignOperator(d *dataTreeNavigator, context Context, expressionNode *ExpressionNode) (Context, error) {
 	assignmentOp := &Operation{OperationType: assignOpType}
-	assignmentOp.UpdateAssign = false
+	assignmentOp.UpdateAssign = true
-
+	selfExpression := &ExpressionNode{Operation: &Operation{OperationType: selfReferenceOpType}}
-	assignmentOpNode := &ExpressionNode{Operation: assignmentOp, Lhs: expressionNode.Lhs, Rhs: createAddOp(expressionNode.Lhs, expressionNode.Rhs)}
+	assignmentOpNode := &ExpressionNode{Operation: assignmentOp, Lhs: expressionNode.Lhs, Rhs: createAddOp(selfExpression, expressionNode.Rhs)}
 	return d.GetMatchingNodes(context, assignmentOpNode)
 }
 

pkg/yqlib/operator_add_test.go

@@ -63,7 +63,7 @@ var addOperatorScenarios = []expressionScenario{
 		},
 	},
 	{
-		description: "Update array (append)",
+		description: "Append to array",
 		document:    `{a: [1,2], b: [3,4]}`,
 		expression:  `.a = .a + .b`,
 		expected: []string{
@@ -71,17 +71,17 @@ var addOperatorScenarios = []expressionScenario{
 		},
 	},
 	{
-		description: "String concatenation",
+		description: "Relative append",
-		document:    `{a: cat, b: meow}`,
+		document:    `a: { a1: {b: [cat]}, a2: {b: [dog]}, a3: {} }`,
-		expression:  `.a = .a + .b`,
+		expression:  `.a[].b += ["mouse"]`,
 		expected: []string{
-			"D0, P[], (doc)::{a: catmeow, b: meow}\n",
+			"D0, P[], (doc)::a: {a1: {b: [cat, mouse]}, a2: {b: [dog, mouse]}, a3: {b: [mouse]}}\n",
 		},
 	},
 	{
-		description: "Relative string concatenation",
+		description: "String concatenation",
 		document:    `{a: cat, b: meow}`,
-		expression:  `.a += .b`,
+		expression:  `.a = .a + .b`,
 		expected: []string{
 			"D0, P[], (doc)::{a: catmeow, b: meow}\n",
 		},
@@ -105,11 +105,11 @@ var addOperatorScenarios = []expressionScenario{
 		},
 	},
 	{
-		description: "Increment number",
+		description: "Increment numbers",
-		document:    `{a: 3}`,
+		document:    `{a: 3, b: 5}`,
-		expression:  `.a += 1`,
+		expression:  `.[] += 1`,
 		expected: []string{
-			"D0, P[], (doc)::{a: 4}\n",
+			"D0, P[], (doc)::{a: 4, b: 6}\n",
 		},
 	},
 	{