Chapter 29: Tech Debt Cleanuplinear-chapter29linear

Co-authored-by: Hsiang-Ying Fu <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: fuhsnn <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: Symious <14933944+symious@users.noreply.github.com>
Co-authored-by: Jun Kawasaki <jun784@gmail.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/src/test/java/com/seaofnodes/simple/ParserTest.java b/src/test/java/com/seaofnodes/simple/ParserTest.java
new file mode 100644
index 00000000..364979f2
--- /dev/null
+++ b/src/test/java/com/seaofnodes/simple/ParserTest.java
@@ -0,0 +1,33 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.parser.Parser;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class ParserTest {
+    @Test public void testDeferredFragments() {
+        // The for update is scanned before the body, then parsed after it.
+        // Delimiters in strings, characters and comments must not end the scan.
+        String[] updates = {"n=n+\") (\"#", "n=n+')'", "n=n+/* ) */2", "n=n+{ -> 2; }()"};
+        String[] results = {"6", "82", "4", "4"};
+        for( int i = 0; i<updates.length; i++ ) {
+            CodeGen code = new CodeGen("int n=0; for(int i=0; i<2; "+updates[i]+") i++; return n;")
+                .driver(CodeGen.Phase.TypeCheck);
+            assertEquals(updates[i],results[i],Eval2.eval(code,0));
+        }
+        // Declared constructor bodies use the same scanner with brace nesting.
+        CodeGen code = new CodeGen("struct Box { int x; new Box={ -> x=\"}\"#; }; }; return new Box().x;")
+            .driver(CodeGen.Phase.TypeCheck);
+        assertEquals("1",Eval2.eval(code,0));
+    }
+
+    @Test public void testUnclosedDeferredFragment() {
+        try {
+            new CodeGen("for(int i=0; i<2; i++").driver(CodeGen.Phase.TypeCheck);
+            fail("Accepted an unterminated for update");
+        } catch( Parser.ParseException e ) {
+            assertEquals("Unclosed for update",e.getMessage());
+        }
+    }
+}