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Types ​

@venizia/ignis-helpers exports the utility types, lazy-value resolvers, and constant classes (HTTP, GRPC, RuntimeModules, ...) that the rest of the IGNIS stack builds on.

In one example ​

TValueOrResolver plus resolveValue is the core pattern for an option that can be given eagerly or lazily.

typescript
import { TValueOrResolver, resolveValue } from '@venizia/ignis-helpers';

function configure(opts: { timeout: TValueOrResolver<number> }) {
  const timeout = resolveValue(opts.timeout);
  // works whether opts.timeout is 5000 or () => 5000
}

configure({ timeout: 5000 });
configure({ timeout: () => 5000 });

How it works ​

  • Escape hatches, not the norm. AnyType and AnyObject exist for the rare case a shape truly cannot be known at compile time. The framework prefers types derived from definitions, like typeof X.schema, everywhere else.
TypeIs
AnyTypeany
AnyObjectRecord<string | symbol | number, any>
  • Nullable and async are explicit. TNullable<T> and ValueOrPromise<T> appear on most framework method signatures. One declared type covers both the sync and the async implementation.
TypeShape
TNullable<T>T | undefined | null
ValueOrPromise<T>T | Promise<T>
  • Resolvers defer construction. TResolver/TAsyncResolver and their TValueOrResolver/TValueOrAsyncResolver unions let a config option be given eagerly or lazily. resolveValue/resolveValueAsync collapse either shape to a value.
  • Class constructors pass through untouched. isClass() detects them, so the resolver never invokes a class as if it were a function. It's re-exported from @venizia/ignis-inversion into helpers.
  • Const classes replace string unions. A class of static readonly fields, for example HTTP or RuntimeModules, is a value namespace. TConstValue<typeof X> derives its own union type from those fields - one declaration, no duplicated string literals.

Common tasks ​

Type an options object with a sync-or-async callback ​

ValueOrPromise<T> is the standard shape for a callback that may or may not be async.

typescript
import { ValueOrPromise } from '@venizia/ignis-helpers';

function connect(opts: { host: string; onReady?: () => ValueOrPromise<void> }) {}

Detect the current runtime ​

RuntimeModules.detect() returns 'bun' when typeof Bun !== 'undefined', 'node' otherwise.

typescript
import { RuntimeModules } from '@venizia/ignis-helpers';

if (RuntimeModules.isBun()) {
  // Bun-specific path
}

Derive a union type from a constant class ​

TConstValue<typeof X> extracts the union of a const class's static values, so the type never drifts from the values.

typescript
import { TConstValue, RuntimeModules } from '@venizia/ignis-helpers';

type TRuntimeModule = TConstValue<typeof RuntimeModules>; // 'node' | 'bun'

Resolve a value that may be eager or lazy, sync or async ​

resolveValueAsync accepts a direct value, a sync resolver, or an async resolver, and always returns a Promise.

typescript
import { TValueOrAsyncResolver, resolveValueAsync } from '@venizia/ignis-helpers';

type ConfigOption = TValueOrAsyncResolver<{ host: string }>;

const fromEnv: ConfigOption = async () => ({ host: process.env.DB_HOST! });
const resolved = await resolveValueAsync(fromEnv);

Look up an HTTP header, content type, or status constant ​

HTTP groups headers, header values, methods, and status codes under one class.

typescript
import { HTTP } from '@venizia/ignis-helpers';

response.header(HTTP.Headers.CONTENT_TYPE, HTTP.HeaderValues.APPLICATION_JSON);
response.status(HTTP.ResultCodes.RS_4.NotFound);

Constrain a mixin's base class ​

TMixinTarget<T> types a mixin factory's Base parameter so the returned class keeps T's shape.

typescript
import { TMixinTarget } from '@venizia/ignis-helpers';

function WithTimestamps<T extends TMixinTarget<BaseEntity>>(Base: T) {
  return class extends Base {
    createdAt = new Date();
  };
}

Flatten an intersection type for readable hover tooltips ​

TPrettify<T> collapses A & B into a single flat object type. IDE tooltips render that far more readably than a chain of intersections.

typescript
import { TPrettify } from '@venizia/ignis-helpers';

type Merged = TPrettify<{ id: string } & { name: string }>;
// Hovers as { id: string; name: string } instead of { id: string } & { name: string }

See the Full reference for every type, resolver function, and constant - including the full HTTP.Headers, HTTP.ResultCodes, and GRPC tables.

See also ​

Files: