diff --git a/ZlibDbg/App/main.vp b/ZlibDbg/App/main.vp
index cbc06ef..2655ce6 100644
--- a/ZlibDbg/App/main.vp
+++ b/ZlibDbg/App/main.vp
@@ -5,8 +5,8 @@ import zlib.zinflate as zinflate
 import zlib.zdef as zdef
 import string
 import stdlib
+import testcheck
 import t, c
-from stdio import printf
 
 
 def fill_data(data: BYTEPTR, size: t.CSizeT, seed: t.CSizeT, repeating: t.CInt):
@@ -26,8 +26,8 @@ def roundtrip(seed: t.CSizeT, size: t.CSizeT, repeating: t.CInt, wbits: t.CInt)
     comp: BYTEPTR = pyzlib.compress(None, data, size,
                                     pyzlib.Z_DEFAULT_COMPRESSION, wbits, c.Addr(out_len))
     if not comp:
-        printf("  [seed=%zu size=%zu rep=%d wbits=%d] COMPRESS FAILED: %d %s\n",
-               seed, size, repeating, wbits, pyzlib.get_error_code(), pyzlib.get_error())
+        testcheck.fail(f"seed={seed} size={size} rep={repeating} wbits={wbits}: "
+                       f"compress 失败 err={pyzlib.get_error_code()} {pyzlib.get_error()}")
         stdlib.free(data)
         return -1
 
@@ -36,17 +36,17 @@ def roundtrip(seed: t.CSizeT, size: t.CSizeT, repeating: t.CInt, wbits: t.CInt)
                                      pyzlib.DEF_BUF_SIZE, c.Addr(dec_len))
     ok: t.CInt = 1
     if not dec:
-        printf("  [seed=%zu size=%zu rep=%d wbits=%d] DECOMPRESS FAILED: err=%d msg=%s (comp=%zu bytes)\n",
-               seed, size, repeating, wbits, pyzlib.get_error_code(), pyzlib.get_error(), out_len)
         ok = 0
+        testcheck.fail(f"seed={seed} size={size} rep={repeating} wbits={wbits}: "
+                       f"decompress 失败 comp={out_len} err={pyzlib.get_error_code()} {pyzlib.get_error()}")
+    elif dec_len != size or string.memcmp(dec, data, size) != 0:
+        ok = 0
+        testcheck.fail(f"seed={seed} size={size} rep={repeating} wbits={wbits}: "
+                       f"内容不匹配 comp={out_len} dec={dec_len}")
     else:
-        printf("  [seed=%zu size=%zu rep=%d wbits=%d] comp=%zu dec=%zu ",
-               seed, size, repeating, wbits, out_len, dec_len)
-        if dec_len != size or string.memcmp(dec, data, size) != 0:
-            printf("CONTENT MISMATCH\n")
-            ok = 0
-        else:
-            printf("OK\n")
+        testcheck.ok(f"seed={seed} size={size} rep={repeating} wbits={wbits}: "
+                     f"comp={out_len} dec={dec_len}")
+
     if dec: stdlib.free(dec)
     stdlib.free(comp)
     stdlib.free(data)
@@ -54,21 +54,22 @@ def roundtrip(seed: t.CSizeT, size: t.CSizeT, repeating: t.CInt, wbits: t.CInt)
 
 
 def main() -> t.CInt:
-    printf("== zlib roundtrip >256B ==\n")
+    testcheck.begin("ZlibDbg: zlib 多 seed/size/wbits 往返")
+
+    testcheck.section("随机数据 (wbits=15)")
     sizes: t.CArray[t.CSizeT, None] = [250, 255, 256, 257, 260, 300, 500, 1000, 4096, 20000]
     n: t.CInt
-    failed: t.CInt = 0
     for n in range(10):
-        if roundtrip(t.CSizeT(n), sizes[n], 0, pyzlib.MAX_WBITS) != 0: failed = 1
-    printf("-- random data done --\n")
+        roundtrip(t.CSizeT(n), sizes[n], 0, pyzlib.MAX_WBITS)
+
+    testcheck.section("重复数据 (wbits=15)")
     sizes2: t.CArray[t.CSizeT, None] = [256, 257, 300, 1000, 20000]
-    n = 0
     for n in range(5):
-        if roundtrip(t.CSizeT(n), sizes2[n], 1, pyzlib.MAX_WBITS) != 0: failed = 1
-    printf("-- repeating data done --\n")
+        roundtrip(t.CSizeT(n), sizes2[n], 1, pyzlib.MAX_WBITS)
+
+    testcheck.section("gzip 容器 (wbits=31)")
     sizes3: t.CArray[t.CSizeT, None] = [300, 1000]
-    n = 0
     for n in range(2):
-        if roundtrip(t.CSizeT(n), sizes3[n], 0, pyzlib.MAX_WBITS + 16) != 0: failed = 1
-    printf("-- gzip container done --\n")
-    return 1 if failed else 0
+        roundtrip(t.CSizeT(n), sizes3[n], 0, pyzlib.MAX_WBITS + 16)
+
+    return testcheck.end()