✨ Add support for parsing a comma separated string list as a map of key-value pairs (#495)

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### Description

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Add support for parsing a comma separated string list as a map of
key-value pairs

### Test Coverage

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Please put an `x` in the correct box e.g. `[x]` to indicate the testing
coverage of this change.
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- [x]  This change is covered by existing or additional automated tests.
- [ ] Manual testing has been performed (and evidence provided) as
automated testing was not feasible.
- [ ] Additional tests are not required for this change (e.g.
documentation update).

---------

Co-authored-by: Adrien CABARBAYE <adrien.cabarbaye@arm.com>

Author: joshjennings98

changes/20240827111953.feature

@@ -0,0 +1 @@
+:sparkles: Add support for parsing a comma separated string list as a map of key-value pairs

utils/collection/parseLists.go

@@ -5,8 +5,11 @@
 package collection
 
 import (
+	"fmt"
 	"strings"
 	"unicode"
+
+	"github.com/ARM-software/golang-utils/utils/commonerrors"
 )
 
 func lineIsOnlyWhitespace(line string) bool {
@@ -52,3 +55,22 @@ func ParseListWithCleanupKeepBlankLines(input string, sep string) (newS []string
 func ParseCommaSeparatedList(input string) []string {
 	return ParseListWithCleanup(input, ",")
 }
+
+// ParseCommaSeparatedListToMap returns a map of key value pairs from a string containing a comma separated list
+func ParseCommaSeparatedListToMap(input string) (pairs map[string]string, err error) {
+	inputSplit := ParseCommaSeparatedList(input)
+	numElements := len(inputSplit)
+
+	if numElements%2 != 0 {
+		err = fmt.Errorf("%w: could not parse comma separated list '%v' into map as it did not have an even number of elements", commonerrors.ErrInvalid, input)
+		return
+	}
+
+	pairs = make(map[string]string, numElements/2)
+	// TODO use slices.Chunk introduced in go 23 when library is upgraded
+	for i := 0; i < numElements; i += 2 {
+		pairs[inputSplit[i]] = inputSplit[i+1]
+	}
+
+	return
+}

utils/collection/parseLists_test.go

@@ -10,7 +10,12 @@ import (
 	"time"
 
 	"github.com/go-faker/faker/v4"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"golang.org/x/exp/maps"
+
+	"github.com/ARM-software/golang-utils/utils/commonerrors"
+	"github.com/ARM-software/golang-utils/utils/commonerrors/errortest"
 )
 
 var (
@@ -87,3 +92,36 @@ func TestParseCommaSeparatedListWithSpacesBetweenWordsKeepBlanks(t *testing.T) {
 	finalList2 := ParseListWithCleanupKeepBlankLines(stringList, ",")
 	require.Equal(t, stringArray, finalList2)
 }
+
+func TestParseCommaSeparatedListToMap(t *testing.T) {
+	for _, test := range []struct {
+		Name     string
+		Input    string
+		Expected map[string]string
+		Err      error
+	}{
+		{"Normal 1", "hello,world", map[string]string{"hello": "world"}, nil},
+		{"Normal 2", "hello,world,adrien,cabarbaye", map[string]string{"hello": "world", "adrien": "cabarbaye"}, nil},
+		{"Normal 2.5", "hello, world, adrien, cabarbaye", map[string]string{"hello": "world", "adrien": "cabarbaye"}, nil},
+		{"Normal 3", "hello,world,adrien,cabarbaye,", map[string]string{"hello": "world", "adrien": "cabarbaye"}, nil},
+		{"Normal 4", "hello,,world,adrien,,,cabarbaye,,,", map[string]string{"hello": "world", "adrien": "cabarbaye"}, nil},
+		{"Normal 5", "hello,world,this,value has spaces", map[string]string{"hello": "world", "this": "value has spaces"}, nil},
+		{"Normal 6", "hello,,world,this,,,value has spaces,,,", map[string]string{"hello": "world", "this": "value has spaces"}, nil},
+		{"Normal 7", "", map[string]string{}, nil},
+		{"Normal 8", ",", map[string]string{}, nil},
+		{"Normal 9", ",,,,,", map[string]string{}, nil},
+		{"Normal 10", ",, ,,  ,", map[string]string{}, nil},
+		{"Bad 1", "one", nil, commonerrors.ErrInvalid},
+		{"Bad 1", "one, two, three", nil, commonerrors.ErrInvalid},
+		{"Bad 2", "one element with spaces", nil, commonerrors.ErrInvalid},
+		{"Bad 3", "one element with spaces and end comma,", nil, commonerrors.ErrInvalid},
+		{"Bad 4", "one element with spaces and multiple end commas,,,", nil, commonerrors.ErrInvalid},
+		{"Bad 5", ",,,one element with spaces and multiple end/beginning commas,,,", nil, commonerrors.ErrInvalid},
+	} {
+		t.Run(test.Name, func(t *testing.T) {
+			pairs, err := ParseCommaSeparatedListToMap(test.Input)
+			errortest.AssertError(t, err, test.Err)
+			assert.True(t, maps.Equal(test.Expected, pairs))
+		})
+	}
+}