Support advanced path expressions

internal/cmdsearch/searchreplace_test.go

@@ -293,8 +293,8 @@ metadata:
  `,
 	},
 	{
-		name: "search by array objects path",
-		args: []string{"--by-path", "spec.foo[1].c"},
+		name: "search replace by array path regex",
+		args: []string{"--by-path", "spec.foo[1]", "--put-literal", "c"},
 		input: `
 apiVersion: apps/v1
 kind: Deployment
@@ -303,22 +303,60 @@ metadata:
 spec:
   replicas: 3
   foo:
-  - c: thing0
-  - c: thing1
-  - c: thing2
----
+  - a
+  - b
+ `,
+		out: `${baseDir}/
+matched 1 field(s)
+${filePath}:  spec.foo[1]: c
+`,
+		expectedResources: `
 apiVersion: apps/v1
-kind: Service
+kind: Deployment
 metadata:
-  name: nginx-service
+  name: nginx-deployment
+spec:
+  replicas: 3
+  foo:
+  - a
+  - c
+ `,
+	},
+	{
+		name: "search replace by array path out of bounds",
+		args: []string{"--by-path", "spec.foo[2]", "--put-literal", "c"},
+		input: `
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: nginx-deployment
+spec:
+  replicas: 3
+  foo:
+  - a
+  - b
  `,
 		out: `${baseDir}/
-matched 1 field(s)
-${filePath}:  spec.foo[1].c: thing1
+matched 0 field(s)
 `,
 		expectedResources: `
 apiVersion: apps/v1
 kind: Deployment
+metadata:
+  name: nginx-deployment
+spec:
+  replicas: 3
+  foo:
+  - a
+  - b
+ `,
+	},
+	{
+		name: "search replace by array objects path",
+		args: []string{"--by-path", "spec.foo[1].c", "--put-literal", "thing-new"},
+		input: `
+apiVersion: apps/v1
+kind: Deployment
 metadata:
   name: nginx-deployment
 spec:
@@ -327,11 +365,22 @@ spec:
   - c: thing0
   - c: thing1
   - c: thing2
----
+ `,
+		out: `${baseDir}/
+matched 1 field(s)
+${filePath}:  spec.foo[1].c: thing-new
+`,
+		expectedResources: `
 apiVersion: apps/v1
-kind: Service
+kind: Deployment
 metadata:
-  name: nginx-service
+  name: nginx-deployment
+spec:
+  replicas: 3
+  foo:
+  - c: thing0
+  - c: thing-new
+  - c: thing2
  `,
 	},
 	{

internal/util/search/pathparser.go

@@ -10,17 +10,84 @@ func (sr *SearchReplace) pathMatch(yamlPath string) bool {
 	if sr.ByPath == "" {
 		return false
 	}
-	inputElems := strings.Split(sr.ByPath, PathDelimiter)
-	traversedElems := strings.Split(strings.Trim(yamlPath, PathDelimiter), PathDelimiter)
-	if len(inputElems) != len(traversedElems) {
-		return false
+
+	patternElems := strings.Split(sr.ByPath, PathDelimiter)
+	yamlPathElems := strings.Split(strings.TrimPrefix(yamlPath, PathDelimiter), PathDelimiter)
+	return backTrackMatch(yamlPathElems, patternElems)
+}
+
+// backTrackMatch matches the traversed yamlPathElems with input(from by-path) patternElems
+// * matches any element, ** matches 0 or more elements, array elements are split and matched
+// refer to pathparser_test.go
+func backTrackMatch(yamlPathElems, patternElems []string) bool {
+	// this is a dynamic programming problem
+	// aim is to check if path array matches pattern array as per above rules
+	yamlPathElemsLen, patternElemsLen := len(yamlPathElems), len(patternElems)
+
+	// initialize a 2d boolean matrix to memorize results
+	// dp[i][j] stores the result, if yamlPath subarray of length i matches
+	// pattern subarray of length j
+	dp := make([][]bool, yamlPathElemsLen+1)
+	for i := range dp {
+		dp[i] = make([]bool, patternElemsLen+1)
+	}
+	dp[0][0] = true
+
+	// edge case 1: when pattern is empty, yamlPath of length grater than 0 doesn't match
+	for i := 1; i < yamlPathElemsLen+1; i++ {
+		dp[i][0] = false
+	}
+
+	// edge case 2: if yamlPath is empty, carry forward the previous result if the pattern element
+	// is `**` as it matches 0 or more elements.
+	for j := 1; j < patternElemsLen+1; j++ {
+		if patternElems[j-1] == "**" {
+			dp[0][j] = dp[0][j-1]
+		}
 	}
-	for i, inputElem := range inputElems {
-		if inputElem != "*" && inputElem != traversedElems[i] {
+
+	// fill rest of the matrix
+	for i := 1; i < yamlPathElemsLen+1; i++ {
+		for j := 1; j < patternElemsLen+1; j++ {
+			if patternElems[j-1] == "**" {
+				// `**` matches multiple elements, so carry forward the result from immediate
+				// neighbors, dp[i-1][j] match empty, dp[i][j-1] match multiple elements
+				dp[i][j] = dp[i][j-1] || dp[i-1][j]
+			} else if patternElems[j-1] == "*" || elementMatch(yamlPathElems[i-1], patternElems[j-1]) {
+				// if there is element match or `*` then get the result from previous diagonal element
+				dp[i][j] = dp[i-1][j-1]
+			}
+		}
+	}
+
+	/*Example matrix for yamlPath = [a,a,b,c,e,b] and pattern [a,*,b,**,b]
+		  a	a	b	c	e	b
+		a	T	F	F	F	F	F
+	  * F	T	F	F	F	F
+		b	F	F	T	F	F	F
+	 ** F	F	T	T	T	T
+		b	F	F	F	F	F	T
+	*/
+
+	return dp[yamlPathElemsLen][patternElemsLen]
+}
+
+// elementMatch matches single element with pattern for single element
+func elementMatch(elem, pattern string) bool {
+	// scalar field case `metadata` matches `metadata`
+	if elem == pattern {
+		return true
+	}
+	// array element e.g. a[*], *[*] and *[b] matches a[b]
+	if strings.Contains(elem, "[") {
+		elemParts := strings.Split(elem, "[")
+		patternParts := strings.Split(pattern, "[")
+		if patternParts[0] != "*" && elemParts[0] != patternParts[0] {
 			return false
 		}
+		return patternParts[1] == "*]" || elemParts[1] == patternParts[1]
 	}
-	return true
+	return false
 }
 
 // isAbsPath checks if input path is absolute and not a path expression

internal/util/search/pathparser_test.go

@@ -32,6 +32,12 @@ var tests = []test{
 		traversedPath: "a.b.c.d",
 		shouldMatch:   true,
 	},
+	{
+		name:          "simple path match with **",
+		byPath:        "a.**.c.*.d",
+		traversedPath: "a.b.c.c.d",
+		shouldMatch:   true,
+	},
 	{
 		name:          "simple path no match with *",
 		byPath:        "a.*.c.*",
@@ -44,6 +50,24 @@ var tests = []test{
 		traversedPath: "a.c[0]",
 		shouldMatch:   true,
 	},
+	{
+		name:          "array path match regex",
+		byPath:        "a.c[*].d.*[*].f",
+		traversedPath: "a.c[0].d.e[1].f",
+		shouldMatch:   true,
+	},
+	{
+		name:          "complex path match regex",
+		byPath:        "**.c[*].d.*[*].**.f",
+		traversedPath: "a.b.c[0].d.e[1].f",
+		shouldMatch:   true,
+	},
+	{
+		name:          "complex path no match regex",
+		byPath:        "**.c[*].d.d.*[*].**.f",
+		traversedPath: "a.c[2].c[0].d.e[1].f",
+		shouldMatch:   false,
+	},
 }
 
 func TestPathMatch(t *testing.T) {

internal/util/search/search.go

@@ -124,7 +124,6 @@ func (sr *SearchReplace) matchAndReplace(node *yaml.Node, path string) error {
 	pathMatch := sr.pathMatch(path)
 	valueMatch := node.Value == sr.ByValue || sr.regexMatch(node.Value)
 
-	// at least one of path or value must be matched
 	if (valueMatch && pathMatch) || (valueMatch && sr.ByPath == "") ||
 		(pathMatch && sr.ByValue == "" && sr.ByValueRegex == "") {
 		sr.Count++
@@ -192,7 +191,11 @@ func (sr *SearchReplace) putLiteral(object *yaml.RNode) error {
 // so that the value can be directly put without needing to traverse the entire node,
 // handles the case of adding non-existent field-value to node
 func (sr *SearchReplace) shouldPutLiteralByPath() bool {
-	return isAbsPath(sr.ByPath) && sr.ByValue == "" && sr.ByValueRegex == "" && sr.PutLiteral != ""
+	return isAbsPath(sr.ByPath) &&
+		!strings.Contains(sr.ByPath, "[") && // TODO: pmarupaka Support appending literal for arrays
+		sr.ByValue == "" &&
+		sr.ByValueRegex == "" &&
+		sr.PutLiteral != ""
 }
 
 // settersValues returns the values for the setters present in PutPattern,