add getIdFieldByStringField()

docs/domains/sobject.md

@@ -29,6 +29,7 @@ Protected methods
 - [getDoubleFieldValues](#getdoublefieldvalues)
 - [getFieldByField](#getfieldbyfield)
 - [getFieldsByField](#getfieldsbyfield)
+- [getIdFieldByStringField](#getidfieldbystringfield)
 - [getIdFieldByIdField](#getidfieldbyidfield)
 - [getIdFieldsByIdField](#getidfieldsbyidfield)
 - [getIdFieldValues](#getidfieldvalues)
@@ -138,6 +139,18 @@ Contacts contacts = Contacts.newInstance(records);
 Map<Object, Set<Object>> contactIdByAccountId = contacts.getFieldsByField(Contact.Id, Contact.AccountId);
 ```
 <br/><br/>
+#### getIdFieldByStringField
+Get a map with the string field as the key and the ID as values. Key fields containing null values are omitted.
+
+`protected Map<String, Id> getIdFieldByStringField(Schema.SObjectField valueField, Schema.SObjectField keyField)`
+
+_Example_
+
+```apex
+Contacts contacts = Contacts.newInstance(records);
+Map<String, Id> accountIdByContactId = contacts.getIdFieldByStringField(Contact.Id, Contact.Name);
+```
+<br/><br/>
 
 #### getIdFieldByIdField
 Get a map with the values of two Id fields. Key fields containing null values are omitted.

sfdx-source/apex-extensions/main/default/classes/domains/fflib_SObjects2.cls

@@ -397,6 +397,35 @@ public virtual class fflib_SObjects2
 		return getRecords().get(0);
 	}
 
+	/**
+	 * Get a map with the values of a String field as key and Id field
+	 * Key fields containing null values are omitted
+	 *
+	 * @param valueField The Id field to use as the Value of the Map
+	 * @param keyField The String field to use as the Key of the map
+	 *
+	 * @return Returns a map with the values of two fields
+	 *
+	 * @example
+	 * Contacts contacts = Contacts.newInstance(records);
+	 * Map<String, Id> accountIdByContactId = contacts.getIdFieldByStringField(Contact.Id, Contact.Name);
+	 */
+	@TestVisible
+	protected virtual Map<String, Id> getIdFieldByStringField(Schema.SObjectField valueField, Schema.SObjectField keyField)
+	{
+		Map<String, Id> result = new Map<String, Id>();
+		for (SObject record : getRecords())
+		{
+			if (record.get(keyField) == null) continue;
+
+			result.put(
+					(String) record.get(keyField),
+					(Id) record.get(valueField)
+			);
+		}
+		return result;
+	}
+
 	/**
 	 * Get a map with the values of two Id fields
 	 * Key fields containing null values are omitted

sfdx-source/apex-extensions/tests/classes/domains/fflib_SObjects2Test.cls

@@ -124,6 +124,19 @@ private class fflib_SObjects2Test
 		// todo - add assertions
 	}
 
+	@IsTest
+	static void itShouldReturnStringById()
+	{
+		final Id accountId = fflib_IDGenerator.generate(Schema.Account.SObjectType);
+		final Account record = new Account(Id = accountId, Name = 'Test');
+		fflib_SObjects2 domain = new fflib_SObjects2(new List<Account>{ record });
+		System.Test.startTest();
+		Map<String, Id> nameById = domain.getIdFieldByStringField(Schema.Account.Id, Schema.Account.Name);
+		System.Test.stopTest();
+		System.assert(nameById.containsKey('Test'));
+		System.assertEquals(accountId, nameById.get(accountId));
+	}
+
 	@IsTest
 	static void itShouldReturnRecordIdById()
 	{