test: observe Web response settlement and preserve failure diagnostics

packages/cli/tests/repl-execution.test.ts

@@ -577,7 +577,7 @@ describe("REPL execution: reopening one history", () => {
     }
   });
 
-  it("X2: a refused reconstruction leaves nothing of itself behind", function* () {
+  it("X2: an unprojectable history refuses atomically and leaves nothing behind", function* () {
     const settled = yield* referenceEvents();
     const holder = execution([settled[0], settled[0], ...settled.slice(1)]);
     const asked = yield* countAsked();
@@ -589,17 +589,10 @@ describe("REPL execution: reopening one history", () => {
     expect(holder.stream.onAppend).toBe(null);
     expect(asked.calls).toBe(0);
     const before = (yield* readAll(holder)).length;
+    expect(before).toBe(settled.length + 1);
     yield* holder.stream.append(settled[settled.length - 1]);
     expect((yield* readAll(holder)).length).toBe(before + 1);
   });
-
-  it("X2: a history this version cannot project refuses before anything runs", function* () {
-    const settled = yield* referenceEvents();
-    const holder = execution([settled[0], settled[0], ...settled.slice(1)]);
-
-    expect(refusal(yield* openReplSession(options(holder))).message).toContain("a second entry");
-    expect((yield* holder.stream.readAll()).length).toBe(settled.length + 1);
-  });
 });
 
 describe("REPL execution: pausing expansion", () => {

packages/web/tests/http-client.ts

@@ -92,6 +92,7 @@ export function useConnection(
     let version = 0;
     let waiting: ((value: void) => void) | undefined;
     const ended = withResolvers<string>();
+    let termination: string | undefined;
 
     const advance = (): void => {
       version += 1;
@@ -105,11 +106,13 @@ export function useConnection(
       advance();
     };
     const onError = (error: Error): void => {
-      ended.resolve(`error:${error.message}`);
+      termination ??= `error:${error.message}`;
+      ended.resolve(termination);
       advance();
     };
     const onClose = (): void => {
-      ended.resolve("close");
+      termination ??= "close";
+      ended.resolve(termination);
       advance();
     };
 
@@ -161,6 +164,11 @@ export function useConnection(
             buffer = parsed.rest;
             return parsed.response;
           }
+          if (termination !== undefined) {
+            throw new Error(
+              `incomplete HTTP response after ${termination}; buffered ${buffer.length} characters; prefix ${JSON.stringify(buffer.slice(0, 160))}`,
+            );
+          }
           yield* untilAfter(seen);
         }
       },