Stream method fixes

Author: ipavlic

README.md

@@ -50,12 +50,6 @@ List<Opportunity> largeOpportunities = SObjectCollection.of(opportunities)
 	.asList();
 ```
 
-### Debug
-
-```apex
-SObjectCollection.of(opportunities).forEach(Fn.Debug);
-```
-
 ### Group
 
 ```apex

force-app/main/default/classes/stream/SObjectStreamFilter.cls

@@ -14,7 +14,6 @@ public with sharing class SObjectStreamFilter extends SObjectStream {
 			SObject nextRecord = recordsIterator.next();
 			if (predicate.call(nextRecord)) {
 				next = nextRecord;
-				hasNext = true;
 				return true;
 			}
 		}
@@ -30,7 +29,7 @@ public with sharing class SObjectStreamFilter extends SObjectStream {
 
 	public virtual override SObject next() {
 		if (hasNext == null) {
-			tryAdvance();
+			hasNext = tryAdvance();
 		}
 		if (hasNext) {
 			SObject nextRecord = next;

force-app/main/default/classes/stream/SObjectStreamRemove.cls

@@ -14,7 +14,6 @@ public with sharing class SObjectStreamRemove extends SObjectStream {
 			SObject nextRecord = recordsIterator.next();
 			if (!predicate.call(nextRecord)) {
 				next = nextRecord;
-				hasNext = true;
 				return true;
 			}
 		}
@@ -30,7 +29,7 @@ public with sharing class SObjectStreamRemove extends SObjectStream {
 
 	public virtual override SObject next() {
 		if (hasNext == null) {
-			tryAdvance();
+			hasNext = tryAdvance();
 		}
 		if (hasNext) {
 			SObject nextRecord = next;

force-app/main/default/classes/test/stream/SObjectStreamTest.cls

@@ -19,6 +19,36 @@ private class SObjectStreamTest {
 		System.Assert.areEqual(accounts[2], filtered[1]);
 	}
 
+	@IsTest
+	private static void filterThrowsExceptionWhenNextIsCalledAndHasNextIsFalse() {
+		List<Account> accounts = new List<Account>{
+				new Account(Name = 'Wrong', AnnualRevenue = 100)
+		};
+		Iterator<SObject> iter = SObjectStream.of(accounts).filter(Fn.Match.field(Account.Name).equals('Ok'));
+
+		try {
+			iter.next();
+			System.Assert.fail();
+		} catch (NoSuchElementException e) {
+			System.Assert.isTrue(true);
+		}
+	}
+
+	@IsTest
+	private static void removeThrowsExceptionWhenNextIsCalledAndHasNextIsFalse() {
+		List<Account> accounts = new List<Account>{
+				new Account(Name = 'Ok', AnnualRevenue = 100)
+		};
+		Iterator<SObject> iter = SObjectStream.of(accounts).remove(Fn.Match.field(Account.Name).equals('Ok'));
+
+		try {
+			iter.next();
+			System.Assert.fail();
+		} catch (NoSuchElementException e) {
+			System.Assert.isTrue(true);
+		}
+	}
+
 	@IsTest
 	private static void testFilterChaining() {
 		List<Account> accounts = new List<Account>{