3 files changed, 85 insertions, 2 deletions
diff --git a/test/unit/input/bysyncify-pure.txt b/test/unit/input/bysyncify-pure.txt
new file mode 100644
index 000000000..1f85db1f1
--- /dev/null
+++ b/test/unit/input/bysyncify-pure.txt
@@ -0,0 +1,17 @@
+(i32.const 100)
+(i32.const 10)
+(i32.const 1)
+(i32.const 20)
+(i32.const 1000)
+(i32.const 2000)
+(i32.const 4000)
+(i32.const 200)
+(i32.const 300)
+(i32.const 400)
+(i32.const 1000)
+(i32.const 3000)
+(i32.const 4000)
+(i32.const 30)
+(i32.const 2)
+(i32.const 40)
+(i32.const 500)
diff --git a/test/unit/input/bysyncify-pure.wast b/test/unit/input/bysyncify-pure.wast
new file mode 100644
index 000000000..b79bfe2b0
--- /dev/null
+++ b/test/unit/input/bysyncify-pure.wast
@@ -0,0 +1,59 @@
+(module
+  (memory 1 1)
+  (import "spectest" "print" (func $print (param i32)))
+  (import "bysyncify" "start_unwind" (func $bysyncify_start_unwind (param i32)))
+  (import "bysyncify" "stop_unwind" (func $bysyncify_stop_unwind))
+  (import "bysyncify" "start_rewind" (func $bysyncify_start_rewind (param i32)))
+  (import "bysyncify" "stop_rewind" (func $bysyncify_stop_rewind))
+  (global $sleeping (mut i32) (i32.const 0))
+  (start $runtime)
+  (func $main
+    (call $print (i32.const 10))
+    (call $before)
+    (call $print (i32.const 20))
+    (call $sleep)
+    (call $print (i32.const 30))
+    (call $after)
+    (call $print (i32.const 40))
+  )
+  (func $before
+    (call $print (i32.const 1))
+  )
+  (func $sleep
+    (call $print (i32.const 1000))
+    (if
+      (i32.eqz (global.get $sleeping))
+      (block
+        (call $print (i32.const 2000))
+        (global.set $sleeping (i32.const 1))
+        (i32.store (i32.const 16) (i32.const 24))
+        (i32.store (i32.const 20) (i32.const 1024))
+        (call $bysyncify_start_unwind (i32.const 16))
+      )
+      (block
+        (call $print (i32.const 3000))
+        (call $bysyncify_stop_rewind)
+        (global.set $sleeping (i32.const 0))
+      )
+    )
+    (call $print (i32.const 4000))
+  )
+  (func $after
+    (call $print (i32.const 2))
+  )
+  (func $runtime
+    (call $print (i32.const 100))
+    ;; call main the first time, let the stack unwind
+    (call $main)
+    (call $print (i32.const 200))
+    (call $bysyncify_stop_unwind)
+    (call $print (i32.const 300))
+    ;; ...can do some async stuff around here...
+    ;; set the rewind in motion
+    (call $bysyncify_start_rewind (i32.const 16))
+    (call $print (i32.const 400))
+    (call $main)
+    (call $print (i32.const 500))
+  )
+)
+
diff --git a/test/unit/test_bysyncify.py b/test/unit/test_bysyncify.py
index 29a8ae7cb..8d5a780e8 100644
--- a/test/unit/test_bysyncify.py
+++ b/test/unit/test_bysyncify.py
@@ -1,11 +1,11 @@
 import os
 
-from scripts.test.shared import WASM_OPT, NODEJS, run_process
+from scripts.test.shared import WASM_OPT, WASM_DIS, WASM_SHELL, NODEJS, run_process
 from utils import BinaryenTestCase
 
 
 class BysyncifyTest(BinaryenTestCase):
-  def test_bysyncify(self):
+  def test_bysyncify_js(self):
     def test(args):
       print(args)
       run_process(WASM_OPT + args + [self.input_path('bysyncify-sleep.wast'), '--bysyncify', '-o', 'a.wasm'])
@@ -19,3 +19,10 @@ class BysyncifyTest(BinaryenTestCase):
     test(['--optimize-level=1'])
     test(['-O3'])
     test(['-Os', '-g'])
+
+  def test_bysyncify_pure_wasm(self):
+    run_process(WASM_OPT + [self.input_path('bysyncify-pure.wast'), '--bysyncify', '-o', 'a.wasm'])
+    run_process(WASM_DIS + ['a.wasm', '-o', 'a.wast'])
+    output = run_process(WASM_SHELL + ['a.wast'], capture_output=True).stdout
+    with open(self.input_path('bysyncify-pure.txt')) as f:
+      self.assertEqual(f.read(), output)