diff --git a/tool/test/org/antlr/v4/testgen/Generator.java b/tool/test/org/antlr/v4/testgen/Generator.java
index 47c4274b3..571df6854 100644
--- a/tool/test/org/antlr/v4/testgen/Generator.java
+++ b/tool/test/org/antlr/v4/testgen/Generator.java
@@ -114,9 +114,48 @@ public class Generator {
 		list.add(buildListeners());
 		list.add(buildParserErrors());
 		list.add(buildParserExec());
+		list.add(buildParseTrees());
 		return list;		
 	}
 
+	private TestFile buildParseTrees() throws Exception {
+		TestFile file = new TestFile("ParseTrees");
+		file.addParserTest(input, "TokenAndRuleContextString", "T", "s", 
+				"x", 
+				"[a, s]\n(a x)\n",
+				null);
+		file.addParserTest(input, "Token2", "T", "s", 
+				"xy", 
+				"(a x y)\n",
+				null);
+		file.addParserTest(input, "test2Alts", "T", "s", 
+				"y", 
+				"(a y)\n",
+				null);
+		file.addParserTest(input, "2AltLoop", "T", "s",
+				"xyyxyxz", 
+				"(a x y y x y x z)\n",
+				null);
+		file.addParserTest(input, "RuleRef", "T", "s", 
+				"yx", 
+				"(a (b y) x)\n",
+				null);
+		// ERRORs not shown. z is colored red in tree view
+		file.addParserTest(input, "ExtraToken", "T", "s", 
+				"xzy", 
+				"(a x z y)\n",
+				null);
+		file.addParserTest(input, "NoViableAlt", "T", "s", 
+				"z",
+				"(a z)\n",
+				null);
+		file.addParserTest(input, "Sync", "T", "s", 
+				"xzyy!", 
+				"(a x z y y !)\n",
+				null);
+		return file;
+	}
+
 	private TestFile buildParserErrors() throws Exception {
 		TestFile file = new TestFile("ParserErrors");
 		file.addParserTest(input, "TokenMismatch", "T", "a", 
diff --git a/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/2AltLoop.st b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/2AltLoop.st
new file mode 100644
index 000000000..0b5bbd977
--- /dev/null
+++ b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/2AltLoop.st
@@ -0,0 +1,11 @@
+grammar <grammarName>;
+s
+@init {
+<buildParseTrees()>
+}
+@after {
+<ToStringTree("$r.ctx"):writeln()>
+}
+  : r=a ;
+a : ('x' | 'y')* 'z'
+  ;
\ No newline at end of file
diff --git a/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/ExtraToken.st b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/ExtraToken.st
new file mode 100644
index 000000000..c5520f0b4
--- /dev/null
+++ b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/ExtraToken.st
@@ -0,0 +1,14 @@
+grammar <grammarName>;
+s
+@init {
+<buildParseTrees()>
+}
+@after {
+<ToStringTree("$r.ctx"):writeln()>
+}
+  : r=a ;
+a : 'x' 'y'
+  ;
+Z : 'z' 
+  ;
+ 
diff --git a/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/NoViableAlt.st b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/NoViableAlt.st
new file mode 100644
index 000000000..3461fe3a4
--- /dev/null
+++ b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/NoViableAlt.st
@@ -0,0 +1,14 @@
+grammar <grammarName>;
+s
+@init {
+<buildParseTrees()>
+}
+@after {
+<ToStringTree("$r.ctx"):writeln()>
+}
+  : r=a ;
+a : 'x' | 'y'
+  ;
+Z : 'z' 
+  ;
+ 
\ No newline at end of file
diff --git a/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/RuleRef.st b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/RuleRef.st
new file mode 100644
index 000000000..2a048fd34
--- /dev/null
+++ b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/RuleRef.st
@@ -0,0 +1,13 @@
+grammar <grammarName>;
+s
+@init {
+<buildParseTrees()>
+}
+@after {
+<ToStringTree("$r.ctx"):writeln()>
+}
+  : r=a ;
+a : b 'x'
+  ;
+b : 'y' 
+  ;
diff --git a/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/Sync.st b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/Sync.st
new file mode 100644
index 000000000..183d1629c
--- /dev/null
+++ b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/Sync.st
@@ -0,0 +1,13 @@
+grammar <grammarName>;
+s
+@init {
+<buildParseTrees()>
+}
+@after {
+<ToStringTree("$r.ctx"):writeln()>
+}
+  : r=a ;
+a : 'x' 'y'* '!'
+  ;
+Z : 'z' 
+  ;
diff --git a/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/Token2.st b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/Token2.st
new file mode 100644
index 000000000..8261e8503
--- /dev/null
+++ b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/Token2.st
@@ -0,0 +1,11 @@
+grammar <grammarName>;
+s
+@init {
+<buildParseTrees()>
+}
+@after {
+<ToStringTree("$r.ctx"):writeln()>
+}
+  : r=a ;
+a : 'x' 'y'
+  ;
diff --git a/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/TokenAndRuleContextString.st b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/TokenAndRuleContextString.st
new file mode 100644
index 000000000..b418522e3
--- /dev/null
+++ b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/TokenAndRuleContextString.st
@@ -0,0 +1,12 @@
+grammar <grammarName>;
+s
+@init {
+<buildParseTrees()>
+}
+@after {
+<ToStringTree("$r.ctx"):writeln()>
+}
+  : r=a ;
+a : 'x' { 
+<writeRuleInvocationStack()>
+} ;
diff --git a/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/test2Alts.st b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/test2Alts.st
new file mode 100644
index 000000000..67eb15bea
--- /dev/null
+++ b/tool/test/org/antlr/v4/testgen/grammars/ParseTrees/test2Alts.st
@@ -0,0 +1,11 @@
+grammar <grammarName>;
+s
+@init {
+<buildParseTrees()>
+}
+@after {
+<ToStringTree("$r.ctx"):writeln()>
+}
+  : r=a ;
+a : 'x' | 'y'
+  ;