variadic string concatenation and initArray methods

Author: stuioco

core/templating/template_helpers.go

@@ -116,8 +116,13 @@ func (t templateHelpers) split(target, separator string) []string {
 	return strings.Split(target, separator)
 }
 
-func (t templateHelpers) concat(val1, val2 string) string {
-	return val1 + val2
+// Concatenates any number of arguments together as strings.
+func (t templateHelpers) concat(args ...interface{}) string {
+	var parts []string
+	for _, arg := range args {
+		parts = append(parts, fmt.Sprint(arg))
+	}
+	return strings.Join(parts, "")
 }
 
 func (t templateHelpers) isNumeric(stringToCheck string) bool {
@@ -566,6 +571,13 @@ func (t templateHelpers) addToArray(key string, value string, output bool, optio
 	}
 }
 
+// Initializes (clears) an array in the template context under the given key.
+func (t templateHelpers) initArray(key string, options *raymond.Options) string {
+	arrayData := options.ValueFromAllCtx("Kvs").(map[string]interface{})
+	arrayData[key] = []string{}
+	return ""
+}
+
 func (t templateHelpers) getArray(key string, options *raymond.Options) []string {
 	arrayData := options.ValueFromAllCtx("Kvs").(map[string]interface{})
 	if array, ok := arrayData[key]; ok {

core/templating/template_helpers_test.go

@@ -3,11 +3,10 @@ package templating
 import (
 	"testing"
 	"time"
+
 	. "github.com/onsi/gomega"
 )
 
-
-
 // mockRaymondOptions is a minimal mock for raymond.Options for testing
 type mockRaymondOptions struct {
 	internalVars map[string]interface{}
@@ -20,7 +19,6 @@ func (m *mockRaymondOptions) ValueFromAllCtx(key string) interface{} {
 	return nil
 }
 
-
 func testNow() time.Time {
 	parsedTime, _ := time.Parse("2006-01-02T15:04:05Z", "2018-01-01T00:00:00Z")
 	return parsedTime
@@ -107,13 +105,22 @@ func Test_split(t *testing.T) {
 }
 
 func Test_concat(t *testing.T) {
+
 	RegisterTestingT(t)
 
 	unit := templateHelpers{}
 
 	Expect(unit.concat("one", " two")).To(Equal("one two"))
 }
 
+func Test_concatWithManyStrings(t *testing.T) {
+	RegisterTestingT(t)
+
+	unit := templateHelpers{}
+
+	Expect(unit.concat("one", " two", " three", " four")).To(Equal("one two three four"))
+}
+
 func Test_length(t *testing.T) {
 	RegisterTestingT(t)
 

core/templating/templating.go

@@ -41,7 +41,6 @@ type Request struct {
 	Host       string
 }
 
-
 type Templator struct {
 	SupportedMethodMap map[string]interface{}
 	TemplateHelper     templateHelpers
@@ -62,7 +61,7 @@ func NewEnrichedTemplator(journal *journal.Journal) *Templator {
 		now:                time.Now,
 		fakerSource:        gofakeit.New(0),
 		TemplateDataSource: templateDataSource,
-		journal: journal,
+		journal:            journal,
 	}
 
 	helperMethodMap["now"] = t.nowHelper
@@ -79,7 +78,24 @@ func NewEnrichedTemplator(journal *journal.Journal) *Templator {
 	helperMethodMap["randomUuid"] = t.randomUuid
 	helperMethodMap["replace"] = t.replace
 	helperMethodMap["split"] = t.split
-	helperMethodMap["concat"] = t.concat
+	//helperMethodMap["concat"] = t.concat
+
+	// Register concatMany to accept a slice of interface{}
+	raymond.RemoveHelper("concat")
+	raymond.RegisterHelper("concat", func(args ...interface{}) string {
+		var parts []string
+		for _, arg := range args {
+			// If arg is a slice, flatten it
+			if s, ok := arg.([]interface{}); ok {
+				for _, v := range s {
+					parts = append(parts, fmt.Sprint(v))
+				}
+			} else {
+				parts = append(parts, fmt.Sprint(arg))
+			}
+		}
+		return strings.Join(parts, "")
+	})
 	helperMethodMap["length"] = t.length
 	helperMethodMap["substring"] = t.substring
 	helperMethodMap["rightmostCharacters"] = t.rightmostCharacters
@@ -111,6 +127,7 @@ func NewEnrichedTemplator(journal *journal.Journal) *Templator {
 	helperMethodMap["subtract"] = t.subtract
 	helperMethodMap["multiply"] = t.multiply
 	helperMethodMap["divide"] = t.divide
+	helperMethodMap["initArray"] = t.initArray
 	helperMethodMap["addToArray"] = t.addToArray
 	helperMethodMap["getArray"] = t.getArray
 	helperMethodMap["putValue"] = t.putValue

core/templating/templating_test.go

@@ -80,6 +80,18 @@ func Test_ApplyTemplate_MatchingRowsCsvAndReturnMatchedString(t *testing.T) {
 	Expect(template).To(Equal(`Test2`))
 }
 
+func Test_ApplyTemplate_InitArray_ClearsArray(t *testing.T) {
+	RegisterTestingT(t)
+
+	template, err := ApplyTemplate(
+		&models.RequestDetails{},
+		make(map[string]string),
+		`{{addToArray 'myArray' 'one' false}}{{addToArray 'myArray' 'two' false}}{{addToArray 'myArray' 'three' false}}{{addToArray 'myArray' 'four' false}}{{addToArray 'myArray' 'five' false}}{{initArray 'myArray'}}{{addToArray 'myArray' 'six' false}}{{#each (getArray 'myArray')}}{{this}}{{/each}}`,
+	)
+
+	Expect(err).To(BeNil())
+	Expect(template).To(Equal("six"))
+}
 func Test_ApplyTemplate_MatchingRowsCsvMissingDataSource(t *testing.T) {
 	RegisterTestingT(t)
 

docs/pages/keyconcepts/templating/templating.rst

@@ -49,7 +49,7 @@ Currently, you can get the following data from request to the response via templ
 Helper Methods
 --------------
 
-Additional data can come from helper methods. These are the ones Hoverfly currently support:
+Additional data can come from helper methods. These are the ones Hoverfly currently supports:
 
 +-----------------------------------------------------------+-----------------------------------------------------------+-----------------------------------------+
 | Description                                               | Example                                                   |  Result                                 |
@@ -529,14 +529,19 @@ In this case, you can use the internal key value data store. The following helpe
 +----------------------------+--------------------------------------------+-----------------------+
 | Get an entry               | ``{{ getValue 'id' }}``                    |  123                  |
 +----------------------------+--------------------------------------------+-----------------------+
-| Add a value to an arra     | ``{{ addToArray 'names' 'John' true }}``   |  John                 |
+| Add a value to an array    | ``{{ addToArray 'names' 'John' true }}``   |  John                 |
+| Get an array               | ``{{ getArray 'names' }}``                 |  ["John"]             |
+| Clear an array             | ``{{ initArray 'names' }}``                |  []                   |
 +----------------------------+--------------------------------------------+-----------------------+
 | Get an array               | ``{{ getArray 'names' }}``                 |  []string{"John"      |
 +----------------------------+--------------------------------------------+-----------------------+
 
+
 ``addToArray`` will create a new array if one doesn't exist. The boolean argument in ``putValue`` and ``addToArray``
 is used to control whether the set value is returned.
 
+``initArray`` will clear an existing array (set it to empty) or create a new empty array if it does not exist. This is useful for resetting arrays inside loops or before reusing them in a template.
+
 .. note::
 
     Each templating session has its own key value store, which means all the data you set will be cleared after the current response is rendered.
@@ -601,7 +606,7 @@ You can use the following helper methods to join, split or replace string values
 +-----------------------------------------------------------+-----------------------------------------------------------+-----------------------------------------+
 | Description                                               | Example                                                   |  Result                                 |
 +===========================================================+===========================================================+=========================================+
-| String concatenate                                        | ``{{ concat 'bee' 'hive' }}``                             |  beehive                                |
+| String concatenate                                        | ``{{ concat 'bee' 'hive' 'buzz' }}``                       |  beehivebuzz                            |
 +-----------------------------------------------------------+-----------------------------------------------------------+-----------------------------------------+
 | String splitting                                          | ``{{ split 'bee,hive' ',' }}``                            |  []string{"bee", "hive"}                |
 +-----------------------------------------------------------+-----------------------------------------------------------+-----------------------------------------+