feat: Create the autoconfigure

lib/autoconfig/AutoConfig.ts

@@ -0,0 +1,70 @@
+import deepmerge from "deepmerge";
+import { AutoConfigure, Effects } from "../types";
+import { Message, MaybePromise, ReadonlyDeep } from ".";
+
+class AutoConfigBuilt<Config> implements AutoConfigure<Config> {
+  constructor(private autoConfig: AutoConfig<Config>) {}
+
+  async check(effects: Effects, config: Config): Promise<void> {
+    for (const [message, configure] of this.autoConfig.getConfigures()) {
+      const value = await configure({ effects, config });
+      if (value !== null) {
+        throw new Error(message);
+      }
+    }
+  }
+  /** This is called after we know that the dependency package needs a new configuration, this would be a transform for defaults */
+  async autoConfigure(effects: Effects, config: Config): Promise<Config> {
+    const input = { effects, config };
+    const newOverwrites = (
+      await Promise.all(this.autoConfig.getConfigures().map((x) => x[1](input)))
+    ).filter((x): x is NonNullable<typeof x> => x !== null);
+    return deepmerge.all([config, ...newOverwrites]);
+  }
+}
+export class AutoConfig<Config> {
+  private constructor(
+    private configures: Array<
+      [
+        Message,
+        (
+          options: Readonly<{ config: Config; effects: Effects }>
+        ) => MaybePromise<null | Partial<Config>>
+      ]
+    >
+  ) {}
+  getConfigures(): ReadonlyDeep<
+    Array<
+      [
+        Message,
+        (
+          options: Readonly<{ config: Config; effects: Effects }>
+        ) => MaybePromise<null | Partial<Config>>
+      ]
+    >
+  > {
+    return this.configures;
+  }
+
+  static autoConfig<Config>(
+    message: Message,
+    configure: (
+      options: Readonly<{ config: Config; effects: Effects }>
+    ) => MaybePromise<null | Partial<Config>>
+  ): AutoConfig<Config> {
+    return new AutoConfig([[message, configure]]);
+  }
+  autoConfig(
+    message: Message,
+    configure: (
+      options: Readonly<{ config: Config; effects: Effects }>
+    ) => MaybePromise<null | Partial<Config>>
+  ): AutoConfig<Config> {
+    this.configures.push([message, configure]);
+    return this;
+  }
+
+  build() {
+    return new AutoConfigBuilt(this);
+  }
+}