Flush messages continuously

This allows @cucumber/query (built into @cucumber/html-formatter) to
maintain state [1] and fixes #931 [2].

[1] https://github.com/cucumber/query/blob/v12.0.1/javascript/src/Query.ts#L46-L59
[2] #931

Author: badeball

features/issues/931.feature

@@ -0,0 +1,42 @@
+# https://github.com/badeball/cypress-cucumber-preprocessor/issues/931
+
+Feature: screenshot of last, failed attempt
+  Background:
+    Given additional preprocessor configuration
+      """
+      {
+        "html": {
+          "enabled": true
+        }
+      }
+      """
+    And a file named "cypress/e2e/a.feature" with:
+      """
+      Feature: a feature
+        Scenario: a scenario
+          Given a failing step
+      """
+    And a file named "cypress/support/step_definitions/steps.js" with:
+      """
+      const { Given } = require("@badeball/cypress-cucumber-preprocessor");
+      Given("a failing step", function() {
+        throw new Error("foobar")
+      })
+      """
+
+  Scenario: retries: 0
+    When I run cypress
+    Then it fails
+    And the report should have an image attachment
+
+  Scenario: retries: 1
+    Given additional Cypress configuration
+      """
+      {
+        "retries": 1
+      }
+      """
+    When I run cypress
+    Then it fails
+    # «Still have», despite having been retried
+    And the report should have an image attachment

features/step_definitions/html_steps.ts

@@ -4,6 +4,11 @@ import path from "path";
 import { promises as fs } from "fs";
 import assert from "assert";
 
+function assertAndReturn<T>(value: T | null | undefined, msg?: string): T {
+  assert(value, msg);
+  return value;
+}
+
 Then("there should be a HTML report", async function () {
   await assert.doesNotReject(
     () => fs.access(path.join(this.tmpDir, "cucumber-report.html")),
@@ -33,3 +38,36 @@ Then("the report should display when last run", async function () {
 
   assert.match(lastRunText, /\d+ seconds? ago/);
 });
+
+Then("the report should have an image attachment", async function () {
+  const dom = await JSDOM.fromFile(
+    path.join(this.tmpDir, "cucumber-report.html"),
+    { runScripts: "dangerously" }
+  );
+
+  const AccordionItemButton = assertAndReturn(
+    dom.window.document.querySelector(
+      '[data-accordion-component="AccordionItemButton"]'
+    ),
+    "Expected to find an AccordionItemButton"
+  );
+
+  assert(AccordionItemButton instanceof dom.window.HTMLElement);
+
+  AccordionItemButton.click();
+
+  const AccordionItemPanel = assertAndReturn(
+    dom.window.document.querySelector(
+      '[data-accordion-component="AccordionItemPanel"]'
+    ),
+    "Expected to find an AccordionItemPanel"
+  );
+
+  assert.match(
+    assertAndReturn(
+      AccordionItemPanel.textContent,
+      "Expected AccordionItemPanel to have textContent"
+    ),
+    /Attached Image/
+  );
+});

lib/create-tests.ts

@@ -145,6 +145,16 @@ function retrieveInternalSuiteProperties():
   return Cypress.env(INTERNAL_SUITE_PROPERTIES);
 }
 
+function flushMessages(messages: CompositionContext["messages"]) {
+  if (messages.enabled) {
+    cy.task(
+      TASK_APPEND_MESSAGES,
+      messages.stack.splice(0, messages.stack.length),
+      { log: false }
+    );
+  }
+}
+
 function findPickleById(context: CompositionContext, astId: string) {
   return assertAndReturn(
     context.pickles.find(
@@ -372,6 +382,8 @@ function createPickle(
       },
     });
 
+    flushMessages(context.messages);
+
     window.testState = {
       gherkinDocument,
       pickles,
@@ -652,22 +664,21 @@ export default function createTests(
       ? parse(environmentTags)
       : noopNode;
 
+  const context: CompositionContext = {
+    registry,
+    gherkinDocument,
+    pickles,
+    testFilter,
+    omitFiltered,
+    messages: {
+      enabled: messagesEnabled,
+      stack: messages,
+    },
+    stepDefinitionHints,
+  };
+
   if (gherkinDocument.feature) {
-    createFeature(
-      {
-        registry,
-        gherkinDocument,
-        pickles,
-        testFilter,
-        omitFiltered,
-        messages: {
-          enabled: messagesEnabled,
-          stack: messages,
-        },
-        stepDefinitionHints,
-      },
-      gherkinDocument.feature
-    );
+    createFeature(context, gherkinDocument.feature);
   }
 
   const isHooksAttached = globalThis[INTERNAL_PROPERTY_NAME];
@@ -806,9 +817,7 @@ export default function createTests(
   });
 
   after(function () {
-    if (messagesEnabled) {
-      cy.task(TASK_APPEND_MESSAGES, messages, { log: false });
-    }
+    flushMessages(context.messages);
   });
 }