changed session id algo

main_test.go

@@ -1179,11 +1179,11 @@ func TestLLMNonStreamingAndHeaders(t *testing.T) {
   }
   // Non-OpenCode endpoints keep the legacy session-affinity headers and must
   // not receive any x-opencode-* headers.
-  if gotLegacy != opencodeSessionID() {
-    t.Errorf("X-Session-Id = %q, want %q", gotLegacy, opencodeSessionID())
+  if !isOpencodeSessionID(gotLegacy) {
+    t.Errorf("X-Session-Id = %q, want a ses_* id", gotLegacy)
   }
-  if gotAffinity != opencodeSessionID() {
-    t.Errorf("x-session-affinity = %q, want %q", gotAffinity, opencodeSessionID())
+  if gotAffinity != gotLegacy {
+    t.Errorf("x-session-affinity = %q, want %q", gotAffinity, gotLegacy)
   }
   if gotOCClient != "" || gotOCReq != "" {
     t.Errorf("unexpected x-opencode headers: client=%q request=%q", gotOCClient, gotOCReq)
@@ -1257,8 +1257,8 @@ func TestApplyLLMHeadersOpencode(t *testing.T) {
   if got := req.Header.Get("x-opencode-project"); got != "global" {
     t.Errorf("x-opencode-project = %q, want global", got)
   }
-  if got := req.Header.Get("x-opencode-session"); got != opencodeSessionID() {
-    t.Errorf("x-opencode-session = %q, want %q", got, opencodeSessionID())
+  if got := req.Header.Get("x-opencode-session"); !isOpencodeSessionID(got) {
+    t.Errorf("x-opencode-session = %q, want a ses_* id", got)
   }
   if got := req.Header.Get("x-opencode-request"); got != "msg_test" {
     t.Errorf("x-opencode-request = %q, want msg_test", got)
@@ -1302,6 +1302,29 @@ func TestApplyLLMHeadersOpencodeAuth(t *testing.T) {
   }
 }
 
+// isOpencodeSessionID reports whether sid matches the Zen session id shape
+// emitted by opencodeSessionID: "ses_" + 12 lowercase hex chars (ending in
+// "ffe") + 14 alphanumeric characters.
+func isOpencodeSessionID(sid string) bool {
+  if !strings.HasPrefix(sid, "ses_") || len(sid) != 30 {
+    return false
+  }
+  for _, c := range sid[4:16] {
+    if !((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f')) {
+      return false
+    }
+  }
+  if sid[13:16] != "ffe" {
+    return false
+  }
+  for _, c := range sid[16:] {
+    if !((c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
+      return false
+    }
+  }
+  return true
+}
+
 func TestOpencodeSessionID(t *testing.T) {
   sid := opencodeSessionID()
   if !strings.HasPrefix(sid, "ses_") {
@@ -1310,11 +1333,26 @@ func TestOpencodeSessionID(t *testing.T) {
   if len(sid) != 30 {
     t.Fatalf("session id length = %d, want 30: %q", len(sid), sid)
   }
-  for _, c := range sid[4:] {
-    if !((c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
-      t.Fatalf("invalid character %c in session id %q", c, sid)
+  // The 12 characters after the "ses_" prefix are lowercase hex (the real
+  // OpenCode ids carry a millisecond timestamp there, ending in "ffe").
+  hexPart := sid[4:16]
+  for _, c := range hexPart {
+    if !((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f')) {
+      t.Fatalf("non-hex character %c in session id prefix %q", c, sid)
     }
   }
+  if hexPart[9:] != "ffe" {
+    t.Fatalf("session id hex marker = %q, want suffix ffe: %q", hexPart[9:], sid)
+  }
+  // The remaining 14 characters are alphanumeric.
+  for _, c := range sid[16:] {
+    if !((c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
+      t.Fatalf("invalid character %c in session id tail %q", c, sid)
+    }
+  }
+  if opencodeSessionID() == sid {
+    t.Fatalf("two consecutive session ids are identical: %q", sid)
+  }
 }
 
 func TestLLMNoAuthHeaderWhenNoKey(t *testing.T) {