feat: add Model::schema_types::<params|result>

src/model.ts

@@ -1,7 +1,7 @@
 import { ParamsField, ResultField } from './query.ts'
 import { schema } from './schema.ts'
 import type { Driver, Constructor } from './util.ts'
-import type { BuiltSchemaField, SchemaGeneric, SchemaInputGeneric } from './schema.ts'
+import type { BuiltSchemaField, SchemaGeneric, SchemaInputGeneric, InferTypes } from './schema.ts'
 import type { Statement, StatementParams, StatementResult } from './statement.ts'
 import type { SqlTemplateArg, RawSqlInterpolationValues } from './query.ts'
 import type { MigrationClass } from './migration.ts'
@@ -16,6 +16,7 @@ interface ModelClass {
   // new (torm: TormBase<Driver>, options: ModelOptions): ModelBase
   new (torm: TormBase<Driver>): ModelBase
 }
+
 interface ModelInstance {
   prepare_queries: (driver?: Driver) => void
 }
@@ -171,7 +172,7 @@ const WithStaticSchema =
   <Class extends Constructor>(base: Class) =>
     <T extends SchemaInputGeneric>(table_name: string, schema_input: T) => {
       return class IncludingStaticSchema extends base {
-        static schema = schema(table_name, schema_input)
+        static schema_types: InferTypes<T>
         static params = IncludingStaticSchema.schema.params
         static result = IncludingStaticSchema.schema.result
       }

src/schema.ts

@@ -3,11 +3,13 @@ import { ParamsField, ResultField } from './query.ts'
 import type { FieldDefinition } from './field.ts'
 
 export type SchemaInputGeneric = Record<string, FieldDefinition<any, any>>
+
 export type SchemaField = {
   table_name: string
   field_name: string
   data_transformers: FieldDefinition<any, any>
 }
+
 export type SchemaFieldGeneric = ParamsField<SchemaField> | ResultField<SchemaField>
 
 export type SchemaGeneric = {
@@ -42,6 +44,19 @@ export type SchemaResult<T extends SchemaInputGeneric> =
   }
 
 
+export type InferTypes<T extends SchemaInputGeneric> = {
+  result: {
+    [K in Extract<keyof T, string>]: T[K] extends FieldDefinition<infer In, any>
+      ? In
+      : never
+  }
+  params: {
+    [K in Extract<keyof T, string>]: T[K] extends FieldDefinition<any, infer Out>
+      ? Out
+      : never
+  }
+}
+
 export interface SchemaOutput<T extends SchemaInputGeneric> {
   params: SchemaParams<T>
   result: SchemaResult<T>
@@ -68,6 +83,7 @@ function schema<T extends SchemaInputGeneric>(table_name: string, schema: T): Sc
   ;(built_result_schema['*'] as any) = Object.values(built_result_schema)
 
   return {
+    schema,
     params: built_params_schema as SchemaParams<T>,
     result: built_result_schema as SchemaResult<T>,
   }