[Cypress runner] Use Cypress Module API to generate Cypress snapshots (#17010)

frontend/test/__runner__/generate-cypress-snapshots.js

+const cypress = require("cypress");
+
+const getConfig = baseUrl => {
+  return {
+    configFile: "frontend/test/__support__/e2e/cypress-snapshots.json",
+    config: {
+      baseUrl,
+    },
+  };
+};
+
+const generateSnapshots = async (baseUrl, exitFunction) => {
+  const snapshotConfig = getConfig(baseUrl);
+
+  try {
+    const results = await cypress.run(snapshotConfig);
+
+    // At least one test failed. We can't continue to the next step.
+    // Cypress tests rely on snapshots correctly generated at this stage.
+    if (results.totalFailed > 0) {
+      await exitFunction(1);
+    }
+
+    // Something went wrong and Cypress failed to even run tests
+    if (results.status === "failed" && results.failures) {
+      console.error(results.message);
+
+      await exitFunction(results.failures);
+    }
+  } catch (e) {
+    console.error("Unable to generate snapshots\n", e);
+
+    await exitFunction(1);
+  }
+};
+
+module.exports = generateSnapshots;

frontend/test/__runner__/run_cypress_tests.js

 import { spawn } from "child_process";
 
 const getVersion = require("./cypress-runner-get-version");
+const generateSnapshots = require("./generate-cypress-snapshots");
 const { printBold, printYellow } = require("./cypress-runner-utils");
 
 // Use require for BackendResource to run it after the mock afterAll has been set
 const BackendResource = require("./backend.js").BackendResource;
 
 const server = BackendResource.get({ dbKey: "" });
+const baseUrl = server.host;
 
 // We currently accept three (optional) command line arguments
 // --open - Opens the Cypress test browser
@@ -29,7 +31,7 @@ const init = async () => {
   await BackendResource.start(server);
 
   printBold("Generating snapshots");
-  await generateSnapshots();
+  await generateSnapshots(baseUrl, cleanup);
 
   printBold("Starting Cypress");
   if (!isOpenMode) {
@@ -108,22 +110,3 @@ launch();
 
 process.on("SIGTERM", cleanup);
 process.on("SIGINT", cleanup);
-
-async function generateSnapshots() {
-  const cypressProcess = spawn(
-    "yarn",
-    [
-      "cypress",
-      "run",
-      "--config-file",
-      "frontend/test/__support__/e2e/cypress-snapshots.json",
-      "--config",
-      `baseUrl=${server.host}`,
-    ],
-    { stdio: "inherit" },
-  );
-
-  return new Promise((resolve, reject) => {
-    cypressProcess.on("exit", resolve);
-  });
-}