Merge pull request #195 from mattfarina/v2deepcopy

V2deepcopy

.travis.yml

@@ -5,6 +5,7 @@ go:
   - 1.10.x
   - 1.11.x
   - 1.12.x
+  - 1.13.x
   - tip
 
 # Setting sudo access to false will let Travis CI use containers rather than

dict.go

@@ -1,6 +1,9 @@
 package sprig
 
-import "github.com/imdario/mergo"
+import (
+	"github.com/imdario/mergo"
+	"github.com/mitchellh/copystructure"
+)
 
 func set(d map[string]interface{}, key string, value interface{}) map[string]interface{} {
 	d[key] = value
@@ -88,13 +91,13 @@ func merge(dst map[string]interface{}, srcs ...map[string]interface{}) interface
 }
 
 func mergeOverwrite(dst map[string]interface{}, srcs ...map[string]interface{}) interface{} {
-  for _, src := range srcs {
+	for _, src := range srcs {
 		if err := mergo.MergeWithOverwrite(&dst, src); err != nil {
 			// Swallow errors inside of a template.
 			return ""
 		}
-  }
-  return dst
+	}
+	return dst
 }
 
 func values(dict map[string]interface{}) []interface{} {
@@ -105,3 +108,12 @@ func values(dict map[string]interface{}) []interface{} {
 
 	return values
 }
+
+func deepCopy(i interface{}) interface{} {
+	c, err := copystructure.Copy(i)
+	if err != nil {
+		panic("deepCopy error: " + err.Error())
+	}
+
+	return c
+}

dict_test.go

@@ -177,7 +177,7 @@ func TestMerge(t *testing.T) {
 		"i": "eye",       // overridden twice
 		"j": "jay",       // overridden and merged
 		"k": map[string]interface{}{
-			"l": true,      // overriden
+			"l": true, // overriden
 		},
 	}
 	assert.Equal(t, expected, dict["dst"])
@@ -222,9 +222,9 @@ func TestMergeOverwrite(t *testing.T) {
 		t.Error(err)
 	}
 	expected := map[string]interface{}{
-		"a": 1,     // key overwritten from src1
-		"b": 2,     // merged from src1
-		"c": 3,     // merged from dst
+		"a": 1, // key overwritten from src1
+		"b": 2, // merged from src1
+		"c": 3, // merged from dst
 		"d": map[string]interface{}{ // deep merge
 			"e": "four",
 			"f": 5,
@@ -233,7 +233,7 @@ func TestMergeOverwrite(t *testing.T) {
 		"h": 10,          // merged from src2
 		"i": "i",         // overwritten twice src2 wins
 		"j": "j",         // overwritten twice src2 wins
-		"k": map[string]interface{} { // deep merge
+		"k": map[string]interface{}{ // deep merge
 			"l": false, // overwritten src1 wins
 		},
 	}
@@ -252,3 +252,17 @@ func TestValues(t *testing.T) {
 		}
 	}
 }
+
+func TestDeepCopy(t *testing.T) {
+	tests := map[string]string{
+		`{{- $d := dict "a" 1 "b" 2 | deepCopy }}{{ values $d | sortAlpha | join "," }}`: "1,2",
+		`{{- $d := dict "a" 1 "b" 2 | deepCopy }}{{ keys $d | sortAlpha | join "," }}`:   "a,b",
+		`{{- $one := dict "foo" (dict "bar" "baz") "qux" true -}}{{ deepCopy $one }}`:    "map[foo:map[bar:baz] qux:true]",
+	}
+
+	for tpl, expect := range tests {
+		if err := runt(tpl, expect); err != nil {
+			t.Error(err)
+		}
+	}
+}

docs/dicts.md

@@ -83,7 +83,13 @@ Merge two or more dictionaries into one, giving precedence to the dest dictionar
 $newdict := merge $dest $source1 $source2
 ```
 
-This is a deep merge operation.
+This is a deep merge operation but not a deep copy operation. Nested objects that
+are merged are the same instance on both dicts. If you want a deep copy along
+with the merge than use the `deepCopy` function along with merging. For example,
+
+```
+deepCopy $source | merge $dest
+```
 
 ## mergeOverwrite
 
@@ -116,7 +122,13 @@ newdict:
 $newdict := mergeOverwrite $dest $source1 $source2
 ```
 
-This is a deep merge operation.
+This is a deep merge operation but not a deep copy operation. Nested objects that
+are merged are the same instance on both dicts. If you want a deep copy along
+with the merge than use the `deepCopy` function along with merging. For example,
+
+```
+deepCopy $source | mergeOverwrite $dest
+```
 
 ## keys
 
@@ -170,6 +182,17 @@ The above returns `list["value1", "value2", "value 3"]`. Note that the `values`
 function gives no guarantees about the result ordering- if you care about this,
 then use `sortAlpha`.
 
+## deepCopy, mustDeepCopy
+
+The `deepCopy` and `mustDeepCopy` functions takes a value and makes a deep copy
+of the value. This includes dicts and other structures. `deepCopy` panics
+when there is a problem while `mustDeepCopy` returns an error to the template
+system when there is an error.
+
+```
+dict "a" 1 "b" 2 | deepCopy
+```
+
 ## A Note on Dict Internals
 
 A `dict` is implemented in Go as a `map[string]interface{}`. Go developers can

docs/index.md

@@ -10,7 +10,7 @@ The Sprig library provides over 70 template functions for Go's template language
 - [Defaults Functions](defaults.md): `default`, `empty`, `coalesce`, `toJson`, `toPrettyJson`, `ternary`
 - [Encoding Functions](encoding.md): `b64enc`, `b64dec`, etc.
 - [Lists and List Functions](lists.md): `list`, `first`, `uniq`, etc.
-- [Dictionaries and Dict Functions](dicts.md): `dict`, `hasKey`, `pluck`, etc.
+- [Dictionaries and Dict Functions](dicts.md): `dict`, `hasKey`, `pluck`, `deepCopy`, etc.
 - [Type Conversion Functions](conversion.md): `atoi`, `int64`, `toString`, etc.
 - [File Path Functions](paths.md): `base`, `dir`, `ext`, `clean`, `isAbs`
 - [Flow Control Functions](flow_control.md): `fail`

functions.go

@@ -211,6 +211,7 @@ var genericMap = map[string]interface{}{
 	"empty":        empty,
 	"coalesce":     coalesce,
 	"compact":      compact,
+	"deepCopy":     deepCopy,
 	"toJson":       toJson,
 	"toPrettyJson": toPrettyJson,
 	"ternary":      ternary,
@@ -301,5 +302,5 @@ var genericMap = map[string]interface{}{
 
 	// URLs:
 	"urlParse": urlParse,
-	"urlJoin": urlJoin,
+	"urlJoin":  urlJoin,
 }

glide.yaml

@@ -15,3 +15,5 @@ import:
   version: ~0.3.7
 - package: github.com/huandu/xstrings
   version: ^1.2
+- package: github.com/mitchellh/copystructure
+  version: ^1.0.0

issue_188_test.go

@@ -0,0 +1,33 @@
+package sprig
+
+import (
+	"testing"
+)
+
+func TestIssue188(t *testing.T) {
+	tests := map[string]string{
+
+		// This first test shows two merges and the merge is NOT A DEEP COPY MERGE.
+		// The first merge puts $one on to $target. When the second merge of $two
+		// on to $target the nested dict brought over from $one is changed on
+		// $one as well as $target.
+		`{{- $target := dict -}}
+			{{- $one := dict "foo" (dict "bar" "baz") "qux" true -}}
+			{{- $two := dict "foo" (dict "bar" "baz2") "qux" false -}}
+			{{- mergeOverwrite $target $one | toString | trunc 0 }}{{ $__ := mergeOverwrite $target $two }}{{ $one }}`: "map[foo:map[bar:baz2] qux:true]",
+
+		// This test uses deepCopy on $one to create a deep copy and then merge
+		// that. In this case the merge of $two on to $target does not affect
+		// $one because a deep copy was used for that merge.
+		`{{- $target := dict -}}
+			{{- $one := dict "foo" (dict "bar" "baz") "qux" true -}}
+			{{- $two := dict "foo" (dict "bar" "baz2") "qux" false -}}
+			{{- deepCopy $one | mergeOverwrite $target | toString | trunc 0 }}{{ $__ := mergeOverwrite $target $two }}{{ $one }}`: "map[foo:map[bar:baz] qux:true]",
+	}
+
+	for tpl, expect := range tests {
+		if err := runt(tpl, expect); err != nil {
+			t.Error(err)
+		}
+	}
+}