From 2d981ae995ad8cfadbb10a8cac0016c4769dd0af Mon Sep 17 00:00:00 2001
From: zxh0 <zhangxiuhong2013@gmail.com>
Date: Tue, 9 Oct 2018 14:12:58 +0800
Subject: [PATCH] + tests

---
 .../zxh/classpy/wasm/WasmBinReader.java       |  1 +
 .../com/github/zxh/classpy/wasm/FuncTest.java | 59 +++++++++++++++++++
 .../github/zxh/classpy/wasm/LEB128Test.java   | 20 +++++++
 3 files changed, 80 insertions(+)
 create mode 100644 classpy-wasm/src/test/java/com/github/zxh/classpy/wasm/FuncTest.java
 create mode 100644 classpy-wasm/src/test/java/com/github/zxh/classpy/wasm/LEB128Test.java

diff --git a/classpy-wasm/src/main/java/com/github/zxh/classpy/wasm/WasmBinReader.java b/classpy-wasm/src/main/java/com/github/zxh/classpy/wasm/WasmBinReader.java
index 59d7a180..70d4930a 100644
--- a/classpy-wasm/src/main/java/com/github/zxh/classpy/wasm/WasmBinReader.java
+++ b/classpy-wasm/src/main/java/com/github/zxh/classpy/wasm/WasmBinReader.java
@@ -4,6 +4,7 @@
 
 import java.nio.ByteOrder;
 
+// https://en.wikipedia.org/wiki/LEB128
 public class WasmBinReader extends BytesReader {
 
     public WasmBinReader(byte[] data) {
diff --git a/classpy-wasm/src/test/java/com/github/zxh/classpy/wasm/FuncTest.java b/classpy-wasm/src/test/java/com/github/zxh/classpy/wasm/FuncTest.java
new file mode 100644
index 00000000..13409930
--- /dev/null
+++ b/classpy-wasm/src/test/java/com/github/zxh/classpy/wasm/FuncTest.java
@@ -0,0 +1,59 @@
+package com.github.zxh.classpy.wasm;
+
+import com.github.zxh.classpy.common.FileComponent;
+import com.github.zxh.classpy.wasm.instructions.Expr;
+import com.github.zxh.classpy.wasm.instructions.Instr;
+import com.github.zxh.classpy.wasm.sections.Code;
+import org.junit.Test;
+
+import java.util.Base64;
+
+public class FuncTest {
+
+    @Test
+    public void read() {
+        String base64 = "AQJ/IAIEfwNAIAAsAAAiAyABLAAAIgRGBEAgAEEBaiEAIAFBAWohAUEAIAJBf2oiAkUNAxoMAQsLIANB/wFxIARB/wFxawVBAAsPCw==";
+        byte[] code = Base64.getDecoder().decode(base64);
+        Code.Func func = new Code.Func();
+        try {
+            func.read(new WasmBinReader(code));
+        } catch (Exception e) {
+            new ExprPrinter().printExpr((Expr) func.getComponents().get(1));
+            throw e;
+        }
+    }
+
+
+    private static class ExprPrinter {
+
+        private int indentation;
+
+        private void printExpr(Expr expr) {
+            for (FileComponent fc : expr.getComponents()) {
+                printInstr((Instr) fc);
+            }
+        }
+
+        private void printInstr(Instr instr) {
+            if (instr.getOpcode() == 0x0B
+                    || instr.getOpcode() == 0x05) {
+                indentation -= 1;
+            }
+            for (int i = 0; i < indentation; i++) {
+                System.out.print("\t");
+            }
+            System.out.println(instr.getName());
+            if (instr.getOpcode() == 0x02
+                    || instr.getOpcode() == 0x03
+                    || instr.getOpcode() == 0x04) {
+                indentation += 1;
+            }
+            for (FileComponent fc : instr.getComponents()) {
+                if (fc instanceof Instr) {
+                    printInstr((Instr) fc);
+                }
+            }
+        }
+    }
+
+}
diff --git a/classpy-wasm/src/test/java/com/github/zxh/classpy/wasm/LEB128Test.java b/classpy-wasm/src/test/java/com/github/zxh/classpy/wasm/LEB128Test.java
new file mode 100644
index 00000000..ffcdc9c1
--- /dev/null
+++ b/classpy-wasm/src/test/java/com/github/zxh/classpy/wasm/LEB128Test.java
@@ -0,0 +1,20 @@
+package com.github.zxh.classpy.wasm;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class LEB128Test {
+
+    @Test
+    public void readU32() {
+        Assert.assertEquals(624485,
+                new WasmBinReader(new byte[] {(byte) 0xE5, (byte) 0x8E, 0x26}).readU32());
+    }
+
+    @Test
+    public void readS32() {
+        Assert.assertEquals(-624485,
+                new WasmBinReader(new byte[] {(byte) 0x9B, (byte) 0xF1, 0x59}).readS32());
+    }
+
+}