Format expected dates in the page rather than in node (#385)

Co-authored-by: Seydi Charyyev <seydi.charyev@gmail.com>

e2e/specs/admin.spec.ts

@@ -1109,12 +1109,17 @@ test("US-102 pause a relay and settle the bill", async ({seed, as}) => {
   const invoices = history.getByRole("listitem")
 
   // The whole period, not just its start: the two invoices meet at a month boundary, so either
-  // date on its own reads the same on both of them.
+  // date on its own reads the same on both of them. Formatted by the browser rather than by node,
+  // so the locale is the one the app rendered with — see dayLabel in dms.spec.ts.
   const period = ({start, end}: {start: number; end: number}) =>
-    `${new Date(start * 1000).toLocaleDateString()} – ${new Date(end * 1000).toLocaleDateString()}`
+    page.evaluate(
+      ([from, to]) =>
+        `${new Date(from * 1000).toLocaleDateString()} – ${new Date(to * 1000).toLocaleDateString()}`,
+      [start, end],
+    )
 
   await expect(invoices.first()).toContainText("$9.00")
-  await expect(invoices.first()).toContainText(period(openPeriod))
+  await expect(invoices.first()).toContainText(await period(openPeriod))
   await expect(invoices.nth(1)).toContainText("$5.00")
-  await expect(invoices.nth(1)).toContainText(period(paidPeriod))
+  await expect(invoices.nth(1)).toContainText(await period(paidPeriod))
 })

e2e/specs/articles-threads.spec.ts

@@ -96,10 +96,14 @@ const expectReactionRoundTrip = async (page: Page, scope: Locator, opener: Locat
   await expect(pill).toHaveCount(0)
 }
 
-// formatTimestamp renders a short date and a short time in the environment's own locale, which node
-// shares, so the date half of it is what a spec can name without pinning a format.
-const shortDate = (seconds: number) =>
-  new Intl.DateTimeFormat(undefined, {dateStyle: "short"}).format(new Date(seconds * 1000))
+// formatTimestamp renders a short date and a short time, so the date half of it is what a spec can
+// name without pinning a format. Formatted by the browser rather than by node, so the locale and the
+// timezone are the ones the app rendered with — see dayLabel in dms.spec.ts.
+const shortDate = (page: Page, seconds: number) =>
+  page.evaluate(
+    ts => new Intl.DateTimeFormat(undefined, {dateStyle: "short"}).format(new Date(ts * 1000)),
+    seconds,
+  )
 
 // The card is a div carrying an overlay link, so it is found by its component rather than by a
 // role — its own contents include a profile button and the room and action links.
@@ -284,7 +288,7 @@ test("US-038 browse, filter, and read articles", async ({seed, as}) => {
   await expect(garden).toContainText("Written by")
   await expect(garden).toContainText("Alice Anderson")
   await expect(garden).toContainText("A short teaser about gardens.")
-  await expect(garden).toContainText(shortDate(at(4, HOUR)))
+  await expect(garden).toContainText(await shortDate(page, at(4, HOUR)))
 
   const authors = page
     .locator("section")
@@ -308,7 +312,7 @@ test("US-038 browse, filter, and read articles", async ({seed, as}) => {
   await expect(page.getByRole("heading", {name: "Tending the Garden"}).first()).toBeVisible()
   await expect(page.locator('img[src="https://images.test/garden.jpg"]')).toBeVisible()
   await expect(page.getByText("A short teaser about gardens.")).toBeVisible()
-  await expect(page.getByText(/^Published /)).toContainText(shortDate(at(4, HOUR)))
+  await expect(page.getByText(/^Published /)).toContainText(await shortDate(page, at(4, HOUR)))
 
   const markdown = page.locator(".content-markdown")
 
@@ -658,7 +662,9 @@ test("US-042 start a thread and see it filed under its room", async ({seed, as})
   await expect(chairs.getByRole("cell").nth(0)).toContainText("Chair procurement")
   await expect(chairs.getByRole("cell").nth(1)).toContainText("Bob Barker")
   await expect(chairs.getByRole("cell").nth(2)).toHaveText("2")
-  await expect(chairs.getByRole("cell").nth(3)).toContainText(shortDate(at(4, HOUR) + 60))
+  await expect(chairs.getByRole("cell").nth(3)).toContainText(
+    await shortDate(page, at(4, HOUR) + 60),
+  )
 
   await pageBar(page).getByRole("button", {name: "Create", exact: true}).click()
 

e2e/specs/community.spec.ts

@@ -63,10 +63,15 @@ const openCard = (card: Locator, title: string) => card.getByText(title).click()
 // its progress bar.
 const pollOption = (page: Page, label: string) => page.locator(".card-sm").filter({hasText: label})
 
-// dateFormatter in @welshman/lib resolves the environment's own locale, which node shares.
-const longDate = (seconds: number) =>
-  new Intl.DateTimeFormat(undefined, {year: "numeric", month: "long", day: "numeric"}).format(
-    new Date(seconds * 1000),
+// The options mirror dateFormatter in @welshman/lib. Formatted by the browser rather than by node,
+// so the locale and the timezone are the ones the app rendered with — see dayLabel in dms.spec.ts.
+const longDate = (page: Page, seconds: number) =>
+  page.evaluate(
+    ts =>
+      new Intl.DateTimeFormat(undefined, {year: "numeric", month: "long", day: "numeric"}).format(
+        new Date(ts * 1000),
+      ),
+    seconds,
   )
 
 // The selections of every poll response this page put on the wire, oldest first. A multiple choice
@@ -204,7 +209,7 @@ test("US-046 create and browse a calendar event", async ({seed, as}) => {
   const market = card("Winter Market")
 
   await expect(market).toBeVisible()
-  await expect(market).toContainText(longDate(Math.floor(target.getTime() / 1000)))
+  await expect(market).toContainText(await longDate(page, Math.floor(target.getTime() / 1000)))
 })
 
 test("US-047 manage your own calendar event", async ({seed, as}) => {
@@ -249,7 +254,7 @@ test("US-047 manage your own calendar event", async ({seed, as}) => {
   const eventCard = page.locator(".card.z-feature")
 
   await expect(page.getByRole("heading", {name: "Harvest Supper", exact: true})).toBeVisible()
-  await expect(eventCard).toContainText(longDate(at(-2, DAY)))
+  await expect(eventCard).toContainText(await longDate(page, at(-2, DAY)))
   await expect(eventCard).toContainText("The Old Mill")
   await expect(eventCard).toContainText("Alice Anderson")