Add a copy button to the final report

tests/browser/final-code-copy.test.js

@@ -0,0 +1,219 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import {
+  FINAL_CODE_NOT_SAVED,
+  reportMarkup,
+  reportMarkdown,
+  mountFinalCodeCopy,
+} from "../../web/render.js";
+import { launchChromium, startStaticServer } from "./source.js";
+
+const session = (code) => ({
+  report: { incomplete: true, summary: "Interview ended.", hintsUsed: 0 },
+  problemTitle: "Example",
+  language: "python",
+  code,
+});
+
+function controls() {
+  const attributes = new Map();
+  const button = {
+    addEventListener: (_, listener) => {
+      button.click = listener;
+    },
+    setAttribute: (name, value) => attributes.set(name, value),
+    removeAttribute: (name) => attributes.delete(name),
+  };
+  const status = { textContent: "" };
+  const root = {
+    querySelector: (selector) =>
+      ({
+        "[data-copy-code]": button,
+        "[data-copy-code-status]": status,
+      })[selector] ?? null,
+  };
+  return { root, button, status, attributes };
+}
+
+test("copy controls appear only for available editor code", () => {
+  assert.match(reportMarkup(session("print(1)")), /data-copy-code>Copy code/);
+  for (const code of ["", " \n\t", undefined, null, FINAL_CODE_NOT_SAVED]) {
+    assert.doesNotMatch(reportMarkup(session(code)), /data-copy-code/);
+  }
+  assert.doesNotMatch(
+    reportMarkup({
+      ...session("print(1)"),
+      board: "data:image/png;base64,YQ==",
+    }),
+    /data-copy-code/,
+  );
+  mountFinalCodeCopy({ querySelector: () => null }, undefined);
+});
+
+test("unsaved code uses the same placeholder in the report and download", () => {
+  assert.ok(
+    reportMarkup(session(FINAL_CODE_NOT_SAVED)).includes(FINAL_CODE_NOT_SAVED),
+  );
+  assert.ok(reportMarkdown(session(null)).includes(FINAL_CODE_NOT_SAVED));
+});
+
+test("copy updates the status emitted by reportMarkup in a browser", async (t) => {
+  const browser = await launchChromium();
+  if (!browser) return t.skip("playwright chromium unavailable");
+  let server;
+  try {
+    const hosted = await startStaticServer();
+    server = hosted.server;
+    const page = await browser.newPage();
+    await page.goto(hosted.base);
+    const code = "\tprint('<&>')  \r\n";
+    const result = await page.evaluate(async (code) => {
+      const { reportMarkup, mountFinalCodeCopy } = await import("/render.js");
+      const root = document.createElement("main");
+      root.innerHTML = reportMarkup({
+        report: { incomplete: true, summary: "Interview ended.", hintsUsed: 0 },
+        problemTitle: "Example",
+        language: "python",
+        code,
+      });
+      document.body.replaceChildren(root);
+      const button = root.querySelector("[data-copy-code]");
+      const status = root.querySelector("[data-copy-code-status]");
+      const writes = [];
+      let finish;
+      mountFinalCodeCopy(root, code, {
+        writeText: (text) => {
+          writes.push(text);
+          return new Promise((resolve) => {
+            finish = resolve;
+          });
+        },
+      });
+      const originalCode = root.querySelector("pre").textContent;
+      button.focus();
+      button.click();
+      const pending = status.textContent;
+      button.click();
+      finish();
+      await Promise.resolve();
+      const success = status.textContent;
+      const enabled = !button.hasAttribute("aria-disabled");
+      const focused = document.activeElement === button;
+      return {
+        writes,
+        pending,
+        success,
+        enabled,
+        focused,
+        unchanged: root.querySelector("pre").textContent === originalCode,
+      };
+    }, code);
+    assert.deepEqual(result, {
+      writes: [code],
+      pending: "Copying...",
+      success: "Copied!",
+      enabled: true,
+      focused: true,
+      unchanged: true,
+    });
+  } finally {
+    await browser.close();
+    if (server) await new Promise((resolve) => server.close(resolve));
+  }
+});
+
+test("copy preserves original whitespace, line endings and HTML characters", async (t) => {
+  t.mock.timers.enable({ apis: ["setTimeout"] });
+  const code = "\tif x < 2:\r\n    print('&<>')  \r\n\r\n";
+  const original = reportMarkup(session(code));
+  const view = controls();
+  const writes = [];
+  mountFinalCodeCopy(view.root, code, {
+    writeText: async (text) => writes.push(text),
+  });
+  await view.button.click();
+  assert.deepEqual(writes, [code]);
+  assert.equal(view.status.textContent, "Copied!");
+  assert.equal(view.attributes.has("aria-disabled"), false);
+  assert.equal(reportMarkup(session(code)), original);
+  t.mock.timers.tick(2000);
+  assert.equal(view.status.textContent, "");
+});
+
+test("repeated copies restart the success feedback timer", async (t) => {
+  t.mock.timers.enable({ apis: ["setTimeout"] });
+  const view = controls();
+  const writes = [];
+  mountFinalCodeCopy(view.root, "code", {
+    writeText: async (text) => writes.push(text),
+  });
+
+  await view.button.click();
+  t.mock.timers.tick(1500);
+  await view.button.click();
+  assert.deepEqual(writes, ["code", "code"]);
+  t.mock.timers.tick(1000);
+  assert.equal(view.status.textContent, "Copied!");
+  t.mock.timers.tick(999);
+  assert.equal(view.status.textContent, "Copied!");
+  t.mock.timers.tick(1);
+  assert.equal(view.status.textContent, "");
+});
+
+test("clipboard failure and unavailable API show an error and allow retry", async (t) => {
+  t.mock.timers.enable({ apis: ["setTimeout"] });
+  for (const clipboard of [
+    undefined,
+    {},
+    {
+      writeText: () => {
+        throw new Error("denied");
+      },
+    },
+    {
+      writeText: async () => {
+        throw new Error("denied");
+      },
+    },
+  ]) {
+    const view = controls();
+    mountFinalCodeCopy(view.root, "code", clipboard);
+    await view.button.click();
+    assert.match(view.status.textContent, /Could not copy code.*manually/);
+    assert.equal(view.attributes.has("aria-disabled"), false);
+  }
+  const view = controls();
+  let reject = true;
+  mountFinalCodeCopy(view.root, "code", {
+    writeText: async () => {
+      if (reject) throw new Error("denied");
+    },
+  });
+  await view.button.click();
+  reject = false;
+  await view.button.click();
+  assert.equal(view.status.textContent, "Copied!");
+});
+
+test("a pending copy ignores duplicate clicks", async (t) => {
+  t.mock.timers.enable({ apis: ["setTimeout"] });
+  const view = controls();
+  let finish;
+  let calls = 0;
+  mountFinalCodeCopy(view.root, "code", {
+    writeText: () => {
+      calls++;
+      return new Promise((resolve) => {
+        finish = resolve;
+      });
+    },
+  });
+  const copying = view.button.click();
+  assert.equal(view.status.textContent, "Copying...");
+  assert.equal(view.attributes.get("aria-disabled"), "true");
+  await view.button.click();
+  assert.equal(calls, 1);
+  finish();
+  await copying;
+  assert.equal(view.status.textContent, "Copied!");
+});

tests/browser/lobby.test.js

@@ -3979,6 +3979,7 @@ for (const storage of ["account", "device"]) {
       }
       await lobby(page);
       const history = page.locator("#attempt-history");
+      assert.equal(await history.locator("[data-copy-code]").count(), 0);
       assert.equal(
         await history.getByRole("button", { name: /^Download report/ }).count(),
         cases.length,
@@ -4463,6 +4464,30 @@ for (const storage of ["device", "account"]) {
           .filter({ hasText: "Your final code" });
         assert.equal(await finalCode.locator("pre").textContent(), shown);
 
+        const copy = row.getByRole("button", {
+          name: "Copy code",
+          exact: true,
+        });
+        if (title === "Kept code") {
+          await page.evaluate(() => {
+            Object.defineProperty(navigator.clipboard, "writeText", {
+              configurable: true,
+              value: async (text) => {
+                window.copiedCode = text;
+              },
+            });
+          });
+          await copy.click();
+          await page.waitForFunction(
+            () =>
+              document.querySelector("[data-copy-code-status]")?.textContent ===
+              "Copied!",
+          );
+          assert.equal(await page.evaluate(() => window.copiedCode), code);
+        } else {
+          assert.equal(await copy.count(), 0);
+        }
+
         const downloading = page.waitForEvent("download");
         await row.getByRole("button", { name: /^Download report/ }).click();
         const chunks = [];

tests/browser/replay-render.test.js

@@ -697,6 +697,7 @@ test("the report card this page renders names no finding either", () => {
       "Communication",
       "Complexity",
       "Contract",
+      "Copy",
       "Done",
       "Download",
       "Edge",

web/app.js

@@ -27,7 +27,12 @@ import {
   pickerEntry,
   progressModelFrom,
 } from "./progress.js";
-import { reportMarkdown, reportMarkup } from "./render.js";
+import {
+  FINAL_CODE_NOT_SAVED,
+  mountFinalCodeCopy,
+  reportMarkdown,
+  reportMarkup,
+} from "./render.js";
 import { downloadMarkdown, reportFilename } from "./download.js";
 import { loadPageMap, loadTopicMap } from "./problem-data.js";
 import {
@@ -1855,9 +1860,10 @@ function renderAttemptHistory(attempts) {
       report: attempt.report,
       problemTitle: attempt.problemTitle,
       language: languageLabel(attempt.language ?? "not recorded"),
-      code: attempt.code ?? "(final code was not saved)",
+      code: attempt.code ?? FINAL_CODE_NOT_SAVED,
       unclearLines: attempt.unclearLines,
     });
+    mountFinalCodeCopy(report, attempt.code);
     report.querySelector(".report-actions")?.remove();
     report.hidden = true;
     open.addEventListener("click", () => {

web/interview.js

@@ -62,6 +62,7 @@ import {
   problemMarkup,
   reportMarkdown,
   reportMarkup,
+  mountFinalCodeCopy,
   reportSaveStatus,
   resultsMarkup,
   runnerStatusMarkup,
@@ -3957,6 +3958,7 @@ function renderReport() {
     saveResult: null,
     unclearLines: unclearLines(),
   });
+  mountFinalCodeCopy(nodes.report, currentCode());
   mountBehavioralReview(nodes.report, state.transcript.values());
 }
 

web/render.js

@@ -16,6 +16,8 @@ import {
   languageLabel,
 } from "./lib.js";
 
+export const FINAL_CODE_NOT_SAVED = "(final code was not saved)";
+
 /// The six coding steps as a whiteboard candidate was shown them, in REACTO
 /// order, so index `i` here is index `i` of `FRAMEWORKS.coding.steps`.
 const BOARD_STEPS = frameworkChecklist("coding", [], "whiteboard").steps;
@@ -419,7 +421,45 @@ export function reportMarkup({
 
 /// The candidate's code, at the foot of an editor interview's card.
 function finalCodeMarkup(language, code) {
-  return `<details><summary>Your final code (${escapeHtml(languageLabel(language) || "not recorded")})</summary><pre>${escapeHtml(code.trimEnd() || "(editor was empty)")}</pre></details>`;
+  const available =
+    typeof code === "string" &&
+    code.trim() !== "" &&
+    code !== FINAL_CODE_NOT_SAVED;
+  return `<section class="final-code"><details><summary>Your final code (${escapeHtml(languageLabel(language) || "not recorded")})</summary><pre>${escapeHtml(code?.trimEnd() || "(editor was empty)")}</pre></details>${available ? '<button type="button" class="secondary" data-copy-code>Copy code</button><span class="muted small" role="status" data-copy-code-status></span>' : ""}</section>`;
+}
+
+/// Keep the original submission in the handler: the rendered preview trims
+/// trailing whitespace and HTML parsing normalizes line endings.
+export function mountFinalCodeCopy(
+  root,
+  code,
+  clipboard = globalThis.navigator?.clipboard,
+) {
+  const button = root.querySelector("[data-copy-code]");
+  if (!button) return;
+  const status = root.querySelector("[data-copy-code-status]");
+  let pending = false;
+  let reset;
+  button.addEventListener("click", async () => {
+    if (pending) return;
+    pending = true;
+    clearTimeout(reset);
+    button.setAttribute("aria-disabled", "true");
+    status.textContent = "Copying...";
+    try {
+      await clipboard.writeText(code);
+      status.textContent = "Copied!";
+      reset = setTimeout(() => {
+        status.textContent = "";
+      }, 2000);
+    } catch {
+      status.textContent =
+        "Could not copy code. Select the code and copy it manually.";
+    } finally {
+      pending = false;
+      button.removeAttribute("aria-disabled");
+    }
+  });
 }
 
 /// A whiteboard interview's work, step by step: the board when each step was
@@ -699,7 +739,7 @@ export function reportMarkdown({
   // the candidate's own download button would do nothing.
   const body =
     code == null
-      ? "(final code was not saved)"
+      ? FINAL_CODE_NOT_SAVED
       : code.trimEnd() || "(editor was empty)";
   const fencedCodeLines = (body, language) => {
     const longestRun = (body.match(/`+/g) || []).reduce(

web/replay.js

@@ -10,7 +10,7 @@
 // `/api/reports` sync module the lobby uses, and repurposing it would break the
 // section it already serves.
 
-import { reportMarkup } from "/render.js";
+import { reportMarkup, mountFinalCodeCopy } from "/render.js";
 import {
   modeLabel,
   replayRows,
@@ -515,6 +515,7 @@ async function loadReport(interviewId, recordingId) {
     unclearLines: unclearLinesOf(saved.unclearLines),
     ...final,
   });
+  mountFinalCodeCopy(nodes.report, final.code);
 }
 
 nodes.more.addEventListener("click", () => void loadList());