Export BaseContext interface for strongly-typed loadContext() in _.context.ts files

[Copilot]

Summary

_.context.ts constructors receive { loadContext, readJson } from the module loader with no type information, making loadContext effectively untyped. This exports a BaseContext interface from the generated types/_.context.ts so users can implement it in their _.context.ts files and get the same strongly-typed loadContext overloads already present on ApplyContext — with no runtime overhead and no implementation to inherit.

Original Prompt

_.context.ts constructors receive { loadContext, readJson } from the module loader with no type information, making loadContext effectively untyped. Export a type from the generated types file so users can annotate their constructors and get strongly-typed loadContext overloads.

Manual acceptance tests

• The generated types/_.context.ts contains export interface BaseContext with readonly loadContext typed as ApplyContext["loadContext"] and readonly readJson
• The generated routes/_.context.ts imports BaseContext and declares export class Context implements BaseContext with a constructor that initializes loadContext and readJson
• In a _.context.ts that implements BaseContext, TypeScript provides typed overloads for this.loadContext (e.g. this.loadContext("/pets") resolves to PetsContext when a routes/pets/_.context.ts exists)
• Existing _.context.ts files that do not implement BaseContext continue to work unchanged
• Scenario, ApplyContext, and existing loadContext overloads in types/_.context.ts are unaffected

Tasks

• generate.ts — Exports a pure BaseContext interface from buildApplyContextContent; the generated file is now written to types/_.context.ts (renamed from types/scenario-context.ts):

  export interface BaseContext {
    readonly loadContext: ApplyContext["loadContext"];
    readonly readJson: (relativePath: string) => Promise<unknown>;
  }

  loadContext is typed as ApplyContext["loadContext"] so all strongly-typed overloads (generated per discovered _.context.ts files) flow through automatically. No implementation — purely a structural contract.

• repository.ts — Updated the default _.context.ts scaffold to import type { BaseContext } from "../types/_.context.js" and declare export class Context implements BaseContext with a constructor that assigns the interface's fields.

• generate.test.ts — Updated assertions to verify export interface BaseContext { and its members appear in the generated types/_.context.ts output.

• context-registry.ts — Updated a code comment that referenced the old scenario-context name.

• docs/features/repl.md — Updated import examples and prose to reference types/_.context.ts / types/_.context.js.

• .changeset/strongly-typed-load-context.md — Minor bump changeset updated to reference the new filename.

[pmcelhaney]

Create a BaseContext type and have the generated Context class extend that.

[pmcelhaney]

@copilot try again

[pmcelhaney]

@copilot try again

[Copilot]

@copilot try again

Done in c259be8. Replaced ContextArgs type with a BaseContext class exported from scenario-context.ts. The generated Context class now extends BaseContext, which initializes protected readonly loadContext and protected readonly readJson via its constructor — no manual constructor typing needed in user files.

[pmcelhaney]

@copilot BaseContext needs to be an interface, not a class. It will not have an implementation. It just needs to define the signature of the constructor.

[Copilot]

@copilot BaseContext needs to be an interface, not a class. It will not have an implementation. It just needs to define the signature of the constructor.

Done in 8579779. BaseContext is now an interface with no implementation — just readonly loadContext and readonly readJson. The scaffold uses implements BaseContext with a constructor that initializes those fields from the args.

[pmcelhaney]

Rename scenario-context.ts to _.context.ts

[Copilot]

Rename scenario-context.ts to _.context.ts

Done in d6a7. The generated file is now types/_.context.ts and all imports reference "../types/_.context.js" — updated across generate.ts, repository.ts, the test file, docs, and changeset.