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feat: Combinators accept any function instead of only composables
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@gustavoguichard
gustavoguichard committed Jun 26, 2024
1 parent f46ee1b commit a40510d
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Showing 21 changed files with 455 additions and 139 deletions.
88 changes: 61 additions & 27 deletions src/combinators.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@ import type {
UnpackData,
} from './types.ts'
import { composable, failure, fromSuccess, success } from './constructors.ts'
import type { Internal } from './internal/types.ts'

/**
* Merges a list of objects into a single object.
Expand Down Expand Up @@ -66,10 +67,10 @@ function pipe<
Fns extends [(...args: any[]) => any, ...Array<(...args: any[]) => any>],
>(
...fns: Fns
): PipeReturn<CanComposeInSequence<Fns>> {
): PipeReturn<CanComposeInSequence<Internal.Composables<Fns>>> {
const last = <T extends any[]>(arr: T): Last<T> => arr.at(-1)
return map(sequence(...fns), last as never) as PipeReturn<
CanComposeInSequence<Fns>
CanComposeInSequence<Internal.Composables<Fns>>
>
}

Expand All @@ -96,11 +97,15 @@ function pipe<
function all<Fns extends Array<(...args: any[]) => any>>(
...fns: Fns
): Composable<
(...args: Parameters<NonNullable<CanComposeInParallel<Fns>[0]>>) => {
[k in keyof Fns]: UnpackData<Composable<Fns[k]>>
(
...args: Parameters<
NonNullable<CanComposeInParallel<Internal.Composables<Fns>>[0]>
>
) => {
[k in keyof Fns]: UnpackData<Internal.Composables<Fns>[k]>
}
> {
return (async (...args) => {
const callable = (async (...args) => {
const results = await Promise.all(fns.map((fn) => composable(fn)(...args)))

if (results.some(({ success }) => success === false)) {
Expand All @@ -109,10 +114,16 @@ function all<Fns extends Array<(...args: any[]) => any>>(

return success((results as Success[]).map(({ data }) => data))
}) as Composable<
(...args: Parameters<NonNullable<CanComposeInParallel<Fns>[0]>>) => {
[k in keyof Fns]: UnpackData<Composable<Fns[k]>>
(
...args: Parameters<
NonNullable<CanComposeInParallel<Internal.Composables<Fns>>[0]>
>
) => {
[k in keyof Fns]: UnpackData<Internal.Composables<Fns>[k]>
}
>
callable.kind = 'composable' as const
return callable
}

/**
Expand All @@ -134,7 +145,10 @@ function collect<Fns extends Record<string, (...args: any[]) => any>>(
): Composable<
(
...args: Parameters<
Exclude<CanComposeInParallel<RecordToTuple<Fns>>[0], undefined>
Exclude<
CanComposeInParallel<RecordToTuple<Internal.Composables<Fns>>>[0],
undefined
>
>
) => {
[key in keyof Fns]: UnpackData<Composable<Fns[key]>>
Expand All @@ -147,7 +161,10 @@ function collect<Fns extends Record<string, (...args: any[]) => any>>(
return map(allFns, mergeObjects) as Composable<
(
...args: Parameters<
Exclude<CanComposeInParallel<RecordToTuple<Fns>>[0], undefined>
Exclude<
CanComposeInParallel<RecordToTuple<Internal.Composables<Fns>>>[0],
undefined
>
>
) => {
[key in keyof Fns]: UnpackData<Composable<Fns[key]>>
Expand All @@ -174,8 +191,8 @@ function sequence<
Fns extends [(...args: any[]) => any, ...Array<(...args: any[]) => any>],
>(
...fns: Fns
): SequenceReturn<CanComposeInSequence<Fns>> {
return (async (...args) => {
): SequenceReturn<CanComposeInSequence<Internal.Composables<Fns>>> {
const callable = (async (...args) => {
const [head, ...tail] = fns

const res = await composable(head)(...args)
Expand All @@ -188,7 +205,9 @@ function sequence<
result.push(res.data)
}
return success(result)
}) as SequenceReturn<CanComposeInSequence<Fns>>
}) as SequenceReturn<CanComposeInSequence<Internal.Composables<Fns>>>
callable.kind = 'composable' as const
return callable
}

/**
Expand All @@ -214,12 +233,14 @@ function map<Fn extends (...args: any[]) => any, O>(
...originalInput: Parameters<Fn>
) => O | Promise<O>,
): Composable<(...args: Parameters<Fn>) => O> {
return (async (...args) => {
const callable = (async (...args) => {
const result = await composable(fn)(...args)
if (!result.success) return failure(result.errors)

return composable(mapper)(result.data, ...args)
}) as Composable<(...args: Parameters<Fn>) => O>
callable.kind = 'composable' as const
return callable
}

/**
Expand All @@ -244,11 +265,13 @@ function mapParameters<
fn: Fn,
mapper: (...args: NewParameters) => Promise<MapperOutput> | MapperOutput,
): MapParametersReturn<Composable<Fn>, NewParameters, MapperOutput> {
return (async (...args) => {
const callable = (async (...args) => {
const output = await composable(mapper)(...args)
if (!output.success) return failure(output.errors)
return composable(fn)(...output.data)
}) as MapParametersReturn<Composable<Fn>, NewParameters, MapperOutput>
callable.kind = 'composable' as const
return callable
}

/**
Expand Down Expand Up @@ -279,7 +302,7 @@ function catchFailure<
: Awaited<ReturnType<C>> | UnpackData<Composable<Fn>>
: Awaited<ReturnType<C>> | UnpackData<Composable<Fn>>
> {
return (async (...args: Parameters<Fn>) => {
const callable = (async (...args: Parameters<Fn>) => {
const res = await composable(fn)(...args)
if (res.success) return success(res.data)
return composable(catcher)(res.errors, ...(args as never))
Expand All @@ -291,6 +314,8 @@ function catchFailure<
: Awaited<ReturnType<C>> | UnpackData<Composable<Fn>>
: Awaited<ReturnType<C>> | UnpackData<Composable<Fn>>
>
callable.kind = 'composable' as const
return callable
}

/**
Expand All @@ -311,7 +336,7 @@ function mapErrors<Fn extends (...args: any[]) => any>(
fn: Fn,
mapper: (err: Error[]) => Error[] | Promise<Error[]>,
): Composable<Fn> {
return (async (...args) => {
const callable = (async (...args) => {
const res = await composable(fn)(...args)
if (res.success) return success(res.data)
const mapped = await composable(mapper)(res.errors)
Expand All @@ -321,6 +346,8 @@ function mapErrors<Fn extends (...args: any[]) => any>(
return failure(mapped.errors)
}
}) as Composable<Fn>
callable.kind = 'composable' as const
return callable
}

/**
Expand Down Expand Up @@ -349,12 +376,16 @@ function trace(
): <Fn extends (...args: any[]) => any>(
fn: Fn,
) => Composable<Fn> {
return ((fn) => async (...args) => {
const originalResult = await composable(fn)(...args)
const traceResult = await composable(traceFn)(originalResult, ...args)
if (traceResult.success) return originalResult
return ((fn) => {
const callable = async (...args: any) => {
const originalResult = await composable(fn)(...args)
const traceResult = await composable(traceFn)(originalResult, ...args)
if (traceResult.success) return originalResult

return failure(traceResult.errors)
return failure(traceResult.errors)
}
callable.kind = 'composable' as const
return callable
}) as <Fn extends (...args: any[]) => any>(
fn: Fn,
) => Composable<Fn>
Expand Down Expand Up @@ -382,24 +413,27 @@ function trace(
* ```
*/
function branch<
SourceComposable extends Composable,
SourceComposable extends (...args: any[]) => any,
Resolver extends (
o: UnpackData<SourceComposable>,
o: UnpackData<Composable<SourceComposable>>,
) => Composable | null | Promise<Composable | null>,
>(
cf: SourceComposable,
// TODO: Make resolver accept plain functions
resolver: Resolver,
): BranchReturn<SourceComposable, Resolver> {
return (async (...args: Parameters<SourceComposable>) => {
const result = await cf(...args)
): BranchReturn<Composable<SourceComposable>, Resolver> {
const callable = (async (...args: Parameters<SourceComposable>) => {
const result = await composable(cf)(...args)
if (!result.success) return result

return composable(async () => {
const nextComposable = await resolver(result.data)
if (typeof nextComposable !== 'function') return result.data
return fromSuccess(nextComposable)(result.data)
})()
}) as BranchReturn<SourceComposable, Resolver>
}) as BranchReturn<Composable<SourceComposable>, Resolver>
;(callable as any).kind = 'composable' as const
return callable
}

export {
Expand Down
70 changes: 37 additions & 33 deletions src/constructors.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@ import type {
Failure,
ParserSchema,
Success,
UnpackData,
} from './types.ts'

/**
Expand Down Expand Up @@ -88,38 +89,6 @@ function fromSuccess<O, P extends any[]>(
}) as (...args: P) => Promise<O>
}

/**
* Creates a composable with unknown input and context that uses schemas to parse them into known types.
* This allows you to code the function with arbitrary types knowinng that they will be enforced in runtime.
* Very useful when piping data coming from any external source into your composables.
* After giving the input and context schemas, you can pass a handler function that takes type safe input and context. That function is gonna catch any errors and always return a Result.
* @param inputSchema the schema for the input
* @param contextSchema the schema for the context
* @returns a handler function that takes type safe input and context
* @example
* const safeFunction = withSchema(
* z.object({ greeting: z.string() }),
* z.object({
* user: z.object({ name: z.string() })
* }),
* )
* const safeGreet = safeFunction(({ greeting }, { user }) => ({
* message: `${greeting} ${user.name}`
* })
*/
function withSchema<I, C>(
inputSchema?: ParserSchema<I>,
contextSchema?: ParserSchema<C>,
): <Output>(
hander: (input: I, context: C) => Output,
) => ComposableWithSchema<Output> {
return (handler) =>
applySchema(
inputSchema,
contextSchema,
)(composable(handler)) as ComposableWithSchema<any>
}

/**
* Takes a composable and creates a composable withSchema that will assert the input and context types according to the given schemas.
* @param fn a composable function
Expand All @@ -146,10 +115,11 @@ function applySchema<ParsedInput, ParsedContext>(
inputSchema?: ParserSchema<ParsedInput>,
contextSchema?: ParserSchema<ParsedContext>,
) {
// TODO: Accept plain functions and equalize with withSchema
return <R, Input, Context>(
fn: Composable<(input: Input, context: Context) => R>,
): ApplySchemaReturn<ParsedInput, ParsedContext, typeof fn> => {
return ((input?: unknown, context?: unknown) => {
const callable = ((input?: unknown, context?: unknown) => {
const ctxResult = (contextSchema ?? alwaysUnknownSchema).safeParse(
context,
)
Expand All @@ -166,9 +136,43 @@ function applySchema<ParsedInput, ParsedContext>(
}
return fn(result.data as Input, ctxResult.data as Context)
}) as ApplySchemaReturn<ParsedInput, ParsedContext, typeof fn>
;(callable as any).kind = 'composable' as const
return callable
}
}

/**
* Creates a composable with unknown input and context that uses schemas to parse them into known types.
* This allows you to code the function with arbitrary types knowinng that they will be enforced in runtime.
* Very useful when piping data coming from any external source into your composables.
* After giving the input and context schemas, you can pass a handler function that takes type safe input and context. That function is gonna catch any errors and always return a Result.
* @param inputSchema the schema for the input
* @param contextSchema the schema for the context
* @returns a handler function that takes type safe input and context
* @example
* const safeFunction = withSchema(
* z.object({ greeting: z.string() }),
* z.object({
* user: z.object({ name: z.string() })
* }),
* )
* const safeGreet = safeFunction(({ greeting }, { user }) => ({
* message: `${greeting} ${user.name}`
* })
*/
function withSchema<I, C>(
inputSchema?: ParserSchema<I>,
contextSchema?: ParserSchema<C>,
): <Fn extends (input: I, context: C) => unknown>(
fn: Fn,
) => ComposableWithSchema<UnpackData<Composable<Fn>>> {
return (handler) =>
applySchema(
inputSchema,
contextSchema,
)(composable(handler)) as ComposableWithSchema<any>
}

const alwaysUnknownSchema: ParserSchema<unknown> = {
safeParse: (data: unknown) => ({ success: true, data }),
}
Expand Down
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