feat: Add a builder for variants

config/list.ts

@@ -1,9 +1,10 @@
 import { ConfigSpec, Tag, UniqueBy, ValueSpecList } from "../types.ts";
-import { BuilderExtract, IBuilder } from "./builder.ts";
+import { IBuilder } from "./builder.ts";
 import { Config } from "./config.ts";
 import { Default, NullableDefault, NumberSpec, StringSpec } from "./value.ts";
 import { Description } from "./value.ts";
 import * as T from "../types.ts";
+import { Variants } from "./variants.ts";
 
 export class List<A extends Tag<"list", ValueSpecList>> extends IBuilder<A> {
   // deno-lint-ignore ban-types
@@ -89,22 +90,16 @@ export class List<A extends Tag<"list", ValueSpecList>> extends IBuilder<A> {
               [key: string]: string;
             };
           };
-          variants: Variants;
+          variants: Variants<B>;
           "display-as": null | string | undefined;
           "unique-by": null | UniqueBy | undefined;
         };
       },
-    Variants extends { [key: string]: Config<ConfigSpec> },
-    B extends ConfigSpec
+    B extends { [key: string]: ConfigSpec }
   >(a: A) {
     const { spec: previousSpec, ...rest } = a;
     const { variants: previousVariants, ...restSpec } = previousSpec;
-    // deno-lint-ignore no-explicit-any
-    const variants: { [K in keyof Variants]: BuilderExtract<Variants[K]> } = {} as any;
-    for (const key in previousVariants) {
-      // deno-lint-ignore no-explicit-any
-      variants[key] = previousVariants[key].build() as any;
-    }
+    const variants = previousVariants.build();
     const spec = {
       ...restSpec,
       variants,

config/mod.ts

@@ -2,3 +2,4 @@ export { Config } from "./config.ts";
 export { List } from "./list.ts";
 export { Pointer } from "./pointer.ts";
 export { Value } from "./value.ts";
+export { Variants } from "./variants.ts";

config/value.ts

@@ -4,6 +4,7 @@ import { BuilderExtract, IBuilder } from "./builder.ts";
 import { Config } from "./config.ts";
 import { List } from "./list.ts";
 import { Pointer } from "./pointer.ts";
+import { Variants } from "./variants.ts";
 
 export type DefaultString =
   | string
@@ -108,22 +109,14 @@ export class Value<A extends ValueSpecAny> extends IBuilder<A> {
             [key: string]: string;
           };
         };
-        variants: Variants;
+        variants: Variants<B>;
         "display-as": string | null;
         "unique-by": _UniqueBy | null;
       },
-    Variants extends {
-      [key: string]: Config<B>;
-    },
-    B extends ConfigSpec
+    B extends { [key: string]: ConfigSpec }
   >(a: A) {
     const { variants: previousVariants, ...rest } = a;
-    // deno-lint-ignore no-explicit-any
-    const variants: { [K in keyof Variants]: BuilderExtract<Variants[K]> } = {} as any;
-    for (const key in previousVariants) {
-      // deno-lint-ignore no-explicit-any
-      variants[key] = previousVariants[key].build() as any;
-    }
+    const variants = previousVariants.build();
     return new Value({
       type: "union" as const,
       ...rest,

config/variants.ts

@@ -0,0 +1,33 @@
+import { ConfigSpec } from "../types.ts";
+import { BuilderExtract, IBuilder } from "./builder.ts";
+import { Config } from "./mod.ts";
+
+export class Variants<A extends { [key: string]: ConfigSpec }> extends IBuilder<A> {
+  static of<
+    A extends {
+      [key: string]: Config<ConfigSpec>;
+    }
+  >(a: A) {
+    // deno-lint-ignore no-explicit-any
+    const variants: { [K in keyof A]: BuilderExtract<A[K]> } = {} as any;
+    for (const key in a) {
+      // deno-lint-ignore no-explicit-any
+      variants[key] = a[key].build() as any;
+    }
+    return new Variants(variants);
+  }
+
+  static empty() {
+    return Variants.of({});
+  }
+  static withVariannt<K extends string, B extends ConfigSpec>(key: K, value: Config<B>) {
+    return Variants.empty().withVariant(key, value);
+  }
+
+  withVariant<K extends string, B extends ConfigSpec>(key: K, value: Config<B>) {
+    return new Variants({
+      ...this.a,
+      [key]: value.build(),
+    } as A & { [key in K]: B });
+  }
+}

mod.ts

@@ -4,4 +4,6 @@ export * as compat from "./compat/mod.ts";
 export * as migrations from "./migrations.ts";
 export * as healthUtil from "./healthUtil.ts";
 export * as util from "./util.ts";
+export * as C from "./config/mod.ts";
+export * as config from "./config/mod.ts";
 export { Backups } from "./backups.ts";