Check that we're not using placeholder unrelocatable values

1 files changed, 50 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryWriterTests.java b/src/test/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryWriterTests.java
new file mode 100644
index 00000000..b7effd0e
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryWriterTests.java
@@ -0,0 +1,50 @@
+package org.shedlang.compiler.backends.wasm.structure.binary;
+
+import org.junit.jupiter.api.Test;
+import org.shedlang.compiler.backends.wasm.structure.ast.linking.WasmMemoryAddress;
+import org.shedlang.compiler.backends.wasm.structure.ast.modules.WasmFuncName;
+import org.shedlang.compiler.backends.wasm.structure.ast.modules.WasmModule;
+
+import java.io.IOException;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.zwobble.precisely.AssertThat.assertThat;
+import static org.zwobble.precisely.Matchers.equalTo;
+
+public class WasmBinaryWriterTests {
+    @Test
+    public void whenNotInRelocatableSectionThenWritingMemoryAddressConstThrowsError() throws IOException {
+        var writer = new WasmBinaryWriter(WasmIndexTable.fromModule(WasmModule.EMPTY));
+
+        var error = assertThrows(
+            IllegalStateException.class,
+            () -> writer.writeSection(
+                WasmSectionId.TYPE,
+                () -> writer.writeMemoryAddressConst(new WasmMemoryAddress("x"))
+            )
+        );
+
+        assertThat(
+            error.getMessage(),
+            equalTo("cannot write memory address outside of relocatable section")
+        );
+    }
+
+    @Test
+    public void whenNotInRelocatableSectionThenWritingTableElementIndexConstThrowsError() throws IOException {
+        var writer = new WasmBinaryWriter(WasmIndexTable.fromModule(WasmModule.EMPTY));
+
+        var error = assertThrows(
+            IllegalStateException.class,
+            () -> writer.writeSection(
+                WasmSectionId.TYPE,
+                () -> writer.writeTableElementIndexConst(new WasmFuncName("f"))
+            )
+        );
+
+        assertThat(
+            error.getMessage(),
+            equalTo("cannot write memory address outside of relocatable section")
+        );
+    }
+}