Chapter 30: Text Formatting and Diagnosticslinear-chapter30

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, 184 insertions, 0 deletions

diff --git a/src/test/java/com/seaofnodes/simple/TerminalInputTest.java b/src/test/java/com/seaofnodes/simple/TerminalInputTest.java
new file mode 100644
index 00000000..bd3831b4
--- /dev/null
+++ b/src/test/java/com/seaofnodes/simple/TerminalInputTest.java
@@ -0,0 +1,184 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.util.Ary;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class TerminalInputTest {
+    @Test public void testLinkOnlyAndEnterEscape() throws Exception {
+        String java=Path.of(System.getProperty("java.home"),"bin","java").toString();
+        String output="build/objs/linkOnlyGame/";
+        // Linking must return without displaying the game or waiting for input.
+        assertEquals("",TestC.exec(20,java,"-ea","-cp",System.getProperty("java.class.path"),
+            Simple.class.getName(),"--link","-L",TestC.RELEASE_SYS_DIR,"-o",output,
+            "docs/examples/TicTacToe.smp"));
+        Path exe=Path.of(output,"TicTacToe"+(TestC.OS.startsWith("Windows") ? ".exe" : ""));
+        assertTrue(Files.isRegularFile(exe));
+        Process child=new ProcessBuilder(exe.toString()).redirectErrorStream(true).start();
+        try {
+            child.getOutputStream().write(new byte[]{'\r','\n',27});
+            child.getOutputStream().flush(); // Keep stdin open: Escape must cause the exit.
+            assertTrue("Escape did not quit",child.waitFor(10,TimeUnit.SECONDS));
+            String text=new String(child.getInputStream().readAllBytes(),StandardCharsets.UTF_8);
+            assertEquals(text,0,child.exitValue());
+            assertTrue(text,text.endsWith("Your move (1-9): \nGoodbye!\n"));
+            assertFalse(text,text.contains("Choose a square"));
+        } finally {
+            child.destroyForcibly();
+        }
+    }
+
+    @Test public void testRedirectedBytesAndEOF() throws IOException {
+        TestC.run("""
+            val main={ u8[~][] args ->
+                if(sys.io.getch()!='5') return 1;
+                if(sys.io.getch()!='q') return 2;
+                if(sys.io.getch()!=-1) return 3;
+                if(sys.libc.errno()!=sys.libc.EOF) return 4;
+                sys.io.p("ok\n"); return 0;
+            };
+            ""","getchBytes",new Ary<>(new String[]{TestC.RELEASE_SYS_DIR}),
+            TestC.CALL_CONVENTION,null,null,"5q","ok\n",-1);
+    }
+
+    @Test public void testReadError() throws IOException {
+        TestC.runSYS("""
+            val main={ u8[~][] args ->
+                sys.io.close(sys.libc.STDIN);
+                if(sys.io.getch()!=-1) return 1;
+                if(sys.libc.errno()<=0) return 2;
+                return 0;
+            };
+            ""","getchError","",-1);
+    }
+
+    @Test public void testGuardsStayInsideFunction() {
+        String src="""
+            val first={ int n -> while(true) { if(n) return 0; return 1; } };
+            val second={ -> int sum=0; for(int i=0; i<3; i++) sum+=i; return sum; };
+            return first(((arg<<32)>>32))+second();
+            """;
+        for(long seed:new long[]{1,123,456}) {
+            CodeGen code=new CodeGen(src,seed,true).driver(CodeGen.Phase.TypeCheck);
+            assertEquals("4",Eval2.eval(code,0));
+            assertEquals("3",Eval2.eval(code,1));
+        }
+    }
+
+    @Test public void testForwardReferenceAfterContinue() {
+        String src="""
+            val run={ int n ->
+                while(n) {
+                    if(n==1) { n=0; continue; }
+                    if(later(n)) return 7;
+                    n=0;
+                }
+                return 3;
+            };
+            val later={ int n -> n==2; };
+            return run(((arg<<32)>>32));
+            """;
+        for(long seed:new long[]{1,123,456}) {
+            CodeGen code=new CodeGen(src,seed,true).driver(CodeGen.Phase.TypeCheck);
+            assertEquals("3",Eval2.eval(code,1));
+            assertEquals("7",Eval2.eval(code,2));
+            assertEquals("3",Eval2.eval(code,3));
+            // The same merge is used by break, including the implicit loop exit.
+            String breaking=src.replace("return 7;","break;").replace("return 3;","return n+3;");
+            CodeGen code2=new CodeGen(breaking,seed,true).driver(CodeGen.Phase.TypeCheck);
+            assertEquals("3",Eval2.eval(code2,1));
+            assertEquals("5",Eval2.eval(code2,2));
+            assertEquals("3",Eval2.eval(code2,3));
+        }
+    }
+
+    @Test public void testForwardReferenceWithLoopLocal() {
+        String src="""
+            val run={ int n ->
+                while(n) {
+                    int key=n;
+                    n--;
+                    if(key==1) continue;
+                    if(later(key)) continue;
+                    return key;
+                }
+                return 0;
+            };
+            val later={ int key -> key==2; };
+            return run(((arg<<32)>>32));
+            """;
+        String nested=src.replace("if(later(key)) continue;",
+            "if(later(key)) { int local=key+1; continue; }");
+        String breaking=nested.replace("int local=key+1; continue;","int local=key+1; break;")
+            .replace("return 0;","return n+10;");
+        String twoRefs=src.replace("return key;","if(other(key)) continue; return key;")
+            .replace("return run(((arg<<32)>>32));","val other={ int key -> key==3; }; return run(((arg<<32)>>32));");
+        for(long seed:new long[]{1,123,456}) {
+            for(String variant:new String[]{src,nested}) {
+                CodeGen code=new CodeGen(variant,seed,true).driver(CodeGen.Phase.TypeCheck);
+                assertEquals("0",Eval2.eval(code,1));
+                assertEquals("0",Eval2.eval(code,2));
+                assertEquals("3",Eval2.eval(code,3));
+            }
+            CodeGen code=new CodeGen(breaking,seed,true).driver(CodeGen.Phase.TypeCheck);
+            assertEquals("10",Eval2.eval(code,1));
+            assertEquals("11",Eval2.eval(code,2));
+            assertEquals("3",Eval2.eval(code,3));
+            CodeGen code2=new CodeGen(twoRefs,seed,true).driver(CodeGen.Phase.TypeCheck);
+            assertEquals("0",Eval2.eval(code2,3));
+            assertEquals("4",Eval2.eval(code2,4));
+        }
+    }
+
+    @Test public void testInteractiveCLIShowsPromptBeforeInput() throws Exception {
+        // Pipe input rather than a terminal: this catches CLI buffering and
+        // requires exactly one byte, with no Enter.
+        String java=Path.of(System.getProperty("java.home"),"bin","java").toString();
+        Process child=new ProcessBuilder(java,"-ea","-cp",System.getProperty("java.class.path"),
+            Simple.class.getName(),"-L",TestC.RELEASE_SYS_DIR,"-o","build/objs/interactiveGame/",
+            "docs/examples/TicTacToe.smp").redirectErrorStream(true).start();
+        try(var reader=Executors.newSingleThreadExecutor()) {
+            try {
+                var prompt=reader.submit(() -> readPrompt(child));
+                String opening=prompt.get(20,TimeUnit.SECONDS);
+                assertTrue(opening,opening.contains("You go first."));
+                assertTrue(opening,opening.contains("   |   |   \n"));
+                assertTrue(child.isAlive());
+                child.getOutputStream().write('5');
+                child.getOutputStream().flush();
+                String turn=reader.submit(() -> readPrompt(child)).get(20,TimeUnit.SECONDS);
+                assertEquals("5\n   |   |   \n---+---+---\n   | X |   \n---+---+---\n   |   |   \n"
+                    +"CPU plays 1.\n O |   |   \n---+---+---\n   | X |   \n---+---+---\n   |   |   \n"
+                    +"Your move (1-9): ",turn);
+                assertTrue(child.isAlive());
+                child.getOutputStream().write(27);
+                child.getOutputStream().flush();
+                assertTrue("Escape did not quit",child.waitFor(10,TimeUnit.SECONDS));
+                assertEquals("\nGoodbye!\n",new String(child.getInputStream().readAllBytes(),StandardCharsets.UTF_8));
+                assertEquals(0,child.exitValue());
+            } finally {
+                child.destroyForcibly();
+            }
+        }
+    }
+
+    private static String readPrompt(Process child) throws IOException {
+        var bytes=new ByteArrayOutputStream();
+        while(bytes.size()<8192) {
+            int ch=child.getInputStream().read();
+            if(ch<0) throw new IOException("Exited before prompt: "+bytes.toString(StandardCharsets.UTF_8));
+            bytes.write(ch);
+            String text=bytes.toString(StandardCharsets.UTF_8);
+            if(text.endsWith("Your move (1-9): ")) return text;
+        }
+        throw new IOException("No prompt: "+bytes.toString(StandardCharsets.UTF_8));
+    }
+}