fix for infinite recursion in Postman var sub (#2780)

* fix for infinite recursion

* oneliner

pkg/sources/postman/substitution.go

@@ -70,8 +70,13 @@ func (s *Source) buildSubstitution(data string, metadata Metadata, combos *map[s
 			if slice.Metadata.CollectionInfo.PostmanID != "" && slice.Metadata.CollectionInfo.PostmanID != metadata.CollectionInfo.PostmanID {
 				continue
 			}
-			// to ensure we don't infinitely recurse, we will trim all `{{}}` from the values before replacement
-			d := strings.ReplaceAll(data, match, strings.Trim(slice.value, "{}"))
+
+			// to ensure we don't infinitely recurse, we will trim all `{{}}` from the values before replacement.
+			// this is to prevent the case where a variable is replaced with a value that contains the same variable causing
+			// an infinite loop
+			removedBrackets := strings.ReplaceAll(strings.ReplaceAll(slice.value, "{{", ""), "}}", "")
+
+			d := strings.ReplaceAll(data, match, removedBrackets)
 			s.buildSubstitution(d, metadata, combos)
 		}
 	}

pkg/sources/postman/substitution_test.go

@@ -68,6 +68,9 @@ func TestSource_BuildSubstituteSet(t *testing.T) {
 	}
 	s.sub.add(Metadata{Type: GLOBAL_TYPE}, "var1", "value1")
 	s.sub.add(Metadata{Type: GLOBAL_TYPE}, "var2", "value2")
+	s.sub.add(Metadata{Type: GLOBAL_TYPE}, "", "value2")
+	s.sub.add(Metadata{Type: GLOBAL_TYPE}, "continuation_token", "'{{continuation_token}}'")     // this caused an infinite loop in the original implementation
+	s.sub.add(Metadata{Type: GLOBAL_TYPE}, "continuation_token2", "'{{{continuation_token2}}}'") // this caused an infinite loop in the original implementation
 
 	metadata := Metadata{
 		Type: GLOBAL_TYPE,
@@ -81,6 +84,8 @@ func TestSource_BuildSubstituteSet(t *testing.T) {
 		{"{{var2}}", []string{"value2"}},
 		{"{{var1}}:{{var2}}", []string{"value1:value2"}},
 		{"no variables", []string{"no variables"}},
+		{"{{var1}}:{{continuation_token}}", []string{"value1:'continuation_token'"}},
+		{"{{var1}}:{{continuation_token2}}", []string{"value1:'{continuation_token2}'"}},
 	}
 
 	for _, tc := range testCases {