Fix bug in calling child flow func call

Author: RainingComputers

pkg/runtimes/dupher/isolate.go

@@ -153,8 +153,8 @@ func (i *Isolate) stepMaybePanic() (bool, []platforms.Event, error) {
 		return done(), events, nil
 
 	case Exit:
-		i.pc++
-		return done(), nil, nil
+		i.pc = len(i.instructions)
+		return true, nil, nil
 
 	case Jump:
 		i.pc = instr.Loc

pkg/runtimes/dupher/isolate_test.go

@@ -158,7 +158,6 @@ func TestIsolate(t *testing.T) {
 					wantEvents: 0,
 					wantVars:   map[string]any{"__return__": 42},
 				},
-				{wantDone: false, wantPC: 2, wantEvents: 0},
 				{
 					wantDone: true,
 					wantPC:   3,

pkg/runtimes/dupher/worker_test.go

@@ -700,6 +700,49 @@ func VoidCallerFlowSpec() {
 				},
 			},
 		},
+		{
+			name:     "child_flow_join_suspend",
+			flowName: "JoinCallerFlow",
+			source: map[string]string{
+				"fetchchild.ds.go": `package main
+
+import (
+	"github.com/RainingComputers/deepslate/prelude"
+	"time"
+)
+
+func FetchChildSpec(url string) int {
+	var result int = 0
+	for {
+		data, err := prelude.HttpRequest("GET", url, map[string]string{}, []byte{})
+		_ = data
+		_ = err
+		result = 42
+		if result == 42 {
+			return result
+		}
+		prelude.Sleep(1 * time.Second)
+	}
+}
+`,
+				"joincaller.ds.go": `package main
+
+func JoinCallerFlowSpec() {
+	url := "http://localhost:18766/health"
+	value := FetchChildSpec(url)
+	_ = value
+}
+`,
+			},
+			steps: []workerTestStep{
+				{
+					sleep: 3 * time.Second,
+					wantVars: map[string]any{
+						"value": 42,
+					},
+				},
+			},
+		},
 		{
 			name:     "select_default",
 			flowName: "SelectDefaultFlow",

pkg/runtimes/dython/deepslate/isolate.py

@@ -122,8 +122,8 @@ def done() -> bool:
             return done(), events
 
         elif isinstance(instr, Exit):
-            self._pc += 1
-            return done(), None
+            self._pc = len(self._instructions)
+            return True, None
 
         elif isinstance(instr, Jump):
             self._pc = instr.loc

pkg/runtimes/dython/deepslate/tests/test_isolate.py

@@ -152,7 +152,6 @@
                     want_events=0,
                     want_vars={"__return__": 42},
                 ),
-                IsolateTestStep(want_done=False, want_pc=2, want_events=0),
                 IsolateTestStep(want_done=True, want_pc=3),
             ],
         ),

pkg/runtimes/dython/deepslate/tests/test_worker.py

@@ -721,6 +721,42 @@ async def select_second_parent_flow() -> None:
             ],
             want_traces=[],
         ),
+        WorkerTestCase(
+            name="child_flow_join_suspend",
+            flow_name="join_caller",
+            source={
+                "suspend_child.py": """\
+from deepslate import flow, http_request, sleep, DSError
+
+
+@flow
+async def suspend_child(url: str) -> bytes:
+    resp: bytes | DSError = b""
+    while True:
+        resp = http_request("GET", url, {}, b"")
+        if isinstance(resp, bytes):
+            return resp
+        sleep(2.0)
+""",
+                "join_caller.py": """\
+from deepslate import flow
+from .suspend_child import suspend_child
+
+
+@flow
+async def join_caller() -> None:
+    url: str = "http://localhost:18769/health"
+    raw: bytes = suspend_child(url)
+""",
+            },
+            steps=[
+                WorkerTestStep(
+                    sleep=2.0,
+                    want_vars={"raw": b'{"Status": "healthy", "Code": 200}'},
+                ),
+            ],
+            want_traces=[],
+        ),
     ],
     ids=lambda t: t.name,
 )