feat: scalar constructor with inference (#954)

Author: jasonkuhrt

src/entrypoints/alpha/_Graffle.ts

@@ -0,0 +1,2 @@
+export * from '../../layers/5_client/client.js'
+export * as Scalars from './scalars.js'

src/entrypoints/alpha/__Graffle.ts

@@ -0,0 +1 @@
+export * as Graffle from './_Graffle.js'

src/entrypoints/alpha/main.ts

@@ -1,3 +1,3 @@
 export { execute } from '../../layers/0_functions/execute.js'
 export { request } from '../../layers/0_functions/request.js'
-export * as Graffle from '../../layers/5_client/client.js'
+export * from './__Graffle.js'

src/entrypoints/alpha/scalars.ts

@@ -1 +1 @@
-export * from '../../layers/1_Schema/Hybrid/types/Scalar/Scalar.js'
+export { create } from '../../layers/1_Schema/Hybrid/types/Scalar/Scalar.js'

src/layers/1_Schema/Hybrid/types/Scalar/Scalar.ts

@@ -2,16 +2,28 @@
 
 import type { GlobalRegistry } from '../../../../2_generator/globalRegistry.js'
 import type { Codec } from './codec.js'
-import { nativeScalarCodecs } from './nativeScalarCodecs.js'
+import { JavaScriptScalarCodecs } from './nativeScalarCodecs.js'
 
-export { nativeScalarCodecs } from './nativeScalarCodecs.js'
+export { JavaScriptScalarCodecs } from './nativeScalarCodecs.js'
 
 export const ScalarKind = `Scalar`
 
 export type ScalarKind = typeof ScalarKind
 
 export type StandardScalarRuntimeTypes = boolean | number | string
 
+export const create = <$Name extends string, $Decoded, $Encoded extends StandardScalarRuntimeTypes>(
+  name: $Name,
+  codec: {
+    encode: (value: $Decoded) => $Encoded
+    decode: (value: $Encoded) => $Decoded
+  },
+): Scalar<$Name, $Decoded, $Encoded> => ({
+  kind: ScalarKind,
+  name: name,
+  codec: codec as any, // eslint-disable-line
+})
+
 export const scalar = <$Name extends string, $Codec extends Codec<any, any>>(
   name: $Name,
   codec: $Codec,
@@ -23,22 +35,23 @@ export const scalar = <$Name extends string, $Codec extends Codec<any, any>>(
 
 export interface Scalar<
   $Name extends string = string,
-  $Codec extends Codec = Codec,
+  $Decoded = unknown,
+  $Encoded extends StandardScalarRuntimeTypes = StandardScalarRuntimeTypes,
 > {
   kind: ScalarKind
   name: $Name
-  codec: $Codec
+  codec: Codec<$Decoded, $Encoded>
 }
 
-export const String = scalar(`String`, nativeScalarCodecs.String)
+export const String = create(`String`, JavaScriptScalarCodecs.String)
 
-export const ID = scalar(`ID`, nativeScalarCodecs.String)
+export const ID = create(`ID`, JavaScriptScalarCodecs.String)
 
-export const Int = scalar(`Int`, nativeScalarCodecs.Number)
+export const Int = create(`Int`, JavaScriptScalarCodecs.Number)
 
-export const Float = scalar(`Float`, nativeScalarCodecs.Number)
+export const Float = create(`Float`, JavaScriptScalarCodecs.Number)
 
-export const Boolean = scalar(`Boolean`, nativeScalarCodecs.Boolean)
+export const Boolean = create(`Boolean`, JavaScriptScalarCodecs.Boolean)
 
 export type ID = typeof ID
 

src/layers/1_Schema/Hybrid/types/Scalar/codec.ts

@@ -1,10 +1,11 @@
 import type { StandardScalarRuntimeTypes } from './Scalar.js'
 
-export const codec = <Decoded = any, Encoded extends StandardScalarRuntimeTypes = StandardScalarRuntimeTypes>(
-  codec: Codec<Decoded, Encoded>,
-) => codec
-
-export type Codec<Decoded = any, Encoded extends StandardScalarRuntimeTypes = StandardScalarRuntimeTypes> = {
-  encode: (value: Decoded) => Encoded
-  decode: (value: Encoded) => Decoded
+export type Codec<$Decoded = any, $Encoded extends StandardScalarRuntimeTypes = StandardScalarRuntimeTypes> = {
+  encode: (value: $Decoded) => $Encoded
+  decode: (value: $Encoded) => $Decoded
 }
+
+export const createCodec = <$Decoded, $Encoded extends StandardScalarRuntimeTypes>(codec: {
+  encode: (value: $Decoded) => $Encoded
+  decode: (value: $Encoded) => $Decoded
+}): Codec<$Decoded, $Encoded> => codec

src/layers/1_Schema/Hybrid/types/Scalar/nativeScalarCodecs.ts

@@ -1,16 +1,16 @@
-import { codec } from './codec.js'
+import { createCodec } from './codec.js'
 
-export const nativeScalarCodecs = {
-  String: codec<string, string>({
-    encode: (value) => value,
-    decode: (value) => value,
+export const JavaScriptScalarCodecs = {
+  String: createCodec({
+    encode: (value: string) => value,
+    decode: (value: string) => value,
   }),
-  Number: codec<number, number>({
-    encode: (value) => value,
-    decode: (value) => value,
+  Number: createCodec({
+    encode: (value: number) => value,
+    decode: (value: number) => value,
   }),
-  Boolean: codec<boolean, boolean>({
-    encode: (value) => value,
-    decode: (value) => value,
+  Boolean: createCodec({
+    encode: (value: boolean) => value,
+    decode: (value: boolean) => value,
   }),
 }

tests/_/customScalarCodecs.ts

@@ -1,9 +1,8 @@
-import { Scalar } from '../../src/layers/1_Schema/__.js'
-import type { Codec } from '../../src/layers/1_Schema/Hybrid/types/Scalar/codec.js'
+import { Graffle } from '../../src/entrypoints/alpha/main.js'
 
-export const Date = Scalar.scalar<'Date', Codec<globalThis.Date, string>>(`Date`, {
-  encode: value => value.toISOString(),
-  decode: value => new globalThis.Date(value),
+export const Date = Graffle.Scalars.create(`Date`, {
+  encode: (value: globalThis.Date) => value.toISOString(),
+  decode: (value: string) => new globalThis.Date(value),
 })
 
 export type Date = typeof Date