| author |  shivam <91240327+shivamhwp@users.noreply.github.com> 2026-10-02 10:34:17+05:30 |
| committer |  GitHub <noreply@github.com> 2026-10-02 10:34:17+05:30 |
| log | 3e60fecf39f37faaca9bdf37e64b7a58229ea547 |
| tree | eff937afe5b4895d12c7317065015095bf248749 |
| parent | 2731929610ecb64617ff5e066980302da328f658 |
| signature | Signed by PGP key B5690EEEBB952194 |
fix(desktop): markdown pages no longer render invisible in the dark-mode browser (#14601)
Co-authored-by: PR Batch Tester <agent@local.test>
Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>2 files changed, 28 insertions(+), 1 deletions(-)
apps
desktop
src
preview
apps/desktop/src/preview/Manager.test.ts+15-1
| ... | ... | @@ -1601,7 +1601,7 @@ describe("PreviewManager", () => { |
| 1601 | 1601 | ), |
| 1602 | 1602 | ); |
| 1603 | 1603 | |
| 1604 | effectIt.effect("emulates prefers-color-scheme and re-applies it across webview swaps", () => | |
| 1604 | effectIt.effect("re-applies opaque base and color scheme across webview swaps", () => | |
| 1605 | 1605 | withManager((manager) => |
| 1606 | 1606 | Effect.gen(function* () { |
| 1607 | 1607 | const makeWebContents = (id: number) => { |
| ... | ... | @@ -1650,6 +1650,16 @@ describe("PreviewManager", () => { |
| 1650 | 1650 | yield* manager.registerWebview("tab_scheme", 42); |
| 1651 | 1651 | yield* Effect.yieldNow; |
| 1652 | 1652 | |
| 1653 | // Guests start with a transparent base; dark-scheme pages need an opaque | |
| 1654 | // one or Chromium skips their dark canvas. | |
| 1655 | const opaqueBase = { | |
| 1656 | color: { r: 255, g: 255, b: 255, a: 1 }, | |
| 1657 | }; | |
| 1658 | expect(first.sendCommand).toHaveBeenCalledWith( | |
| 1659 | "Emulation.setDefaultBackgroundColorOverride", | |
| 1660 | opaqueBase, | |
| 1661 | ); | |
| 1662 | ||
| 1653 | 1663 | yield* manager.setColorScheme("tab_scheme", "dark"); |
| 1654 | 1664 | |
| 1655 | 1665 | expect(first.sendCommand).toHaveBeenCalledWith("Emulation.setEmulatedMedia", { |
| ... | ... | @@ -1662,6 +1672,10 @@ describe("PreviewManager", () => { |
| 1662 | 1672 | yield* manager.registerWebview("tab_scheme", 43); |
| 1663 | 1673 | yield* Effect.yieldNow; |
| 1664 | 1674 | |
| 1675 | expect(replacement.sendCommand).toHaveBeenCalledWith( | |
| 1676 | "Emulation.setDefaultBackgroundColorOverride", | |
| 1677 | opaqueBase, | |
| 1678 | ); | |
| 1665 | 1679 | expect(replacement.sendCommand).toHaveBeenCalledWith("Emulation.setEmulatedMedia", { |
| 1666 | 1680 | features: [{ name: "prefers-color-scheme", value: "dark" }], |
| 1667 | 1681 | }); |
apps/desktop/src/preview/Manager.ts+13
| ... | ... | @@ -1418,6 +1418,19 @@ const makeNativeOperations = Effect.fn("PreviewManager.makeOperations")(function |
| 1418 | 1418 | ), |
| 1419 | 1419 | { concurrency: "unbounded", discard: true }, |
| 1420 | 1420 | ); |
| 1421 | // Electron gives `<webview>` guests a transparent base background, and | |
| 1422 | // Chromium only paints a dark canvas for dark color-scheme pages over an | |
| 1423 | // opaque base. Without this, dark-scheme pages with no background of | |
| 1424 | // their own (text/plain, e.g. .md files) render white text on white. | |
| 1425 | // White matches the webview's existing white backing, so light pages look | |
| 1426 | // the same; Chromium still swaps in its dark canvas for dark-scheme pages. | |
| 1427 | yield* attemptPromise( | |
| 1428 | { operation: "initializeDebugger.defaultBackground", webContentsId: wc.id }, | |
| 1429 | () => | |
| 1430 | wcDebugger.sendCommand("Emulation.setDefaultBackgroundColorOverride", { | |
| 1431 | color: { r: 255, g: 255, b: 255, a: 1 }, | |
| 1432 | }), | |
| 1433 | ); | |
| 1421 | 1434 | return [ |
| 1422 | 1435 | control, |
| 1423 | 1436 | replaceMap(sessions, (copy) => { |