Coding conventions

Match the established owner before introducing a new pattern. Repository checks enforce many of these rules as contracts.

Code and imports

• Use @trinity/* public entrypoints across libraries and relative imports within one library.
• Keep features independent; shared product behavior belongs to data access or application orchestration.
• Keep matrix-js-sdk in approved data-access adapters and Matrix modeling utilities.
• Treat deprecations as errors; migrate to the supported API instead of suppressing the diagnostic.

Angular and state

• Keep component TypeScript, template, stylesheet, and spec separate.
• Use trn selectors, OnPush, current template control flow, signal inputs/outputs, and Signal Forms for new forms.
• Expose state as read-only signals and model one-shot actions as cold finite Observables.
• End component-owned subscriptions with lifecycle cleanup.

UI and tests

• Consume reusable UI through @trinity/components/*; keep vendors behind the public tier.
• Use semantic tokens rather than literal colors and do not use ::ng-deep.
• Preserve established data-testid hooks.
• Put unit specs beside their source and use real-browser evidence for layout and interaction claims.
• Keep screenshots, traces, prototypes, and pixel baselines in ignored output.

User-facing copy

The domain language in CONTEXT.md capitalises Account, Room and Space for code and design discussion. User-visible text does not: it reads as plain English.

• Sentence case. Buttons, menu items, headings, tooltips and accessible names capitalise only the first word and proper names (“Create room”, “System status”, “Close edit history”).
• No capitalised domain nouns. Write “room”, “space”, “account”, “conversation”, “light mode” mid-sentence. Name a menu or tab by its exact label when you point at it (“Open Space settings”).
• Room, not channel. Never write “channel” in copy. The sidebar, threads, pins, empty states and prompts all say “room”.
• Plain words. Say “this account”, not “the opening Account”; “devices”, not “sessions”, in Settings.
• Direct messages. The rail button that opens the direct-message list is “Direct messages”, the same as the sidebar title. “Home” is not a user-facing term.
• Sign out vs Remove account. “Remove account from this device” deletes this device’s copy of an account (credentials, drafts, cached messages, keys) and signs it out of its homeserver. “Sign out” appears only in Settings › Devices, where it ends another device’s session; the device you are using has no “Sign out” action.
• Dismissing. “Cancel” abandons an action in progress (a form, prompt or confirmation). “Close” leaves a view that has nothing to abandon (a panel, viewer or read-only dialog). “Done” ends a completed flow. Never use “OK”: TrnAlertService requires an explicit confirmText that names the action (“Leave”, “Delete”).
• Delete vs Remove. “Delete” destroys data and cannot be undone (a message, a past version). “Remove” takes an item out of a container (a room from a space, an account from this device).
• Retry. A button with no object reads “Try again”; one that names its object may read “Retry local setup”. Error sentences end with “Try again.”
• Menu items on a message use the bare verb (“Reply”, “Report”, “Delete”). Add an object only when the verb is ambiguous (“Copy text”, “Copy link”).
• Errors name the cause in plain language and never show SDK text, status lines or URLs. Route Matrix failures through describeMatrixRequestFailure or matrixRequestErrorHandling, and show the message next to the field it concerns, linked with aria-describedby.

Run formatting, affected project checks, and architecture guards appropriate to the change. Read Angular components and testing strategy for implementation detail.