poke

Author: hipstersmoothie

packages/core/src/index.ts

@@ -63,6 +63,9 @@ export type JimpInstanceMethods<T> = {
   [K in keyof T]: JimpInstanceMethod<T, T[K]>;
 };
 
+// type for instantiated class
+type Instance<T> = T extends Constructor<infer U> ? U : never;
+
 type JimpSupportedFormats<U> = U extends Format<infer M>[] ? M : never;
 
 export * from "./utils/constants.js";
@@ -127,6 +130,20 @@ export class Jimp<
       Constructor<Jimp<SupportedFormats, NewFormats>>;
   }
 
+  static build<S extends Constructor<any>>(this: S) {
+    // a generic type that relpaces the return type of the methods in the class
+    type ReplaceReturnTypeInMethodMap<T> = {
+      [K in keyof T]: T[K] extends (...args: infer Args) => infer R
+        ? (...args: Args) => FullConstructorWithMethods
+        : T[K];
+    };
+
+    type FullConstructorWithMethods = Instance<S>;
+
+    return class extends this {} as typeof this &
+      Constructor<ReplaceReturnTypeInMethodMap<FullConstructorWithMethods>>;
+  }
+
   constructor(options: JimpOptions = {}) {
     const classConstructor = this.constructor as typeof Jimp;
 

packages/jimp/src/index.ts

@@ -5,4 +5,18 @@ import blit from "@jimp/plugin-blit";
 
 import png from "@jimp/js-png";
 
-export const Jimp = JimpCustom.addFormat(png).plugin(blit).plugin(crop);
+export const Jimp = JimpCustom
+  // .addFormat(png)
+  .plugin(blit)
+  .plugin(crop)
+  .build();
+
+const image = new Jimp();
+
+image
+  .blit({ src: image, x: 0, y: 0 })
+  .crop(0, 0, image.bitmap.width, image.bitmap.height);
+
+image
+  .crop(0, 0, image.bitmap.width, image.bitmap.height)
+  .blit({ src: image, x: 0, y: 0 });

plugins/plugin-blit/src/index.ts

@@ -1,6 +1,23 @@
 import { JimpClass } from "@jimp/types";
 import { limit255, scan } from "@jimp/utils";
 
+export interface BlitOptions<I extends JimpClass> {
+  /** This image to blit on to the current image */
+  src: I;
+  /** the x position to blit the image */
+  x: number;
+  /** the y position to blit the image */
+  y: number;
+  /** the x position from which to crop the source image */
+  srcX?: number;
+  /** the y position from which to crop the source image */
+  srcY?: number;
+  /** the width to which to crop the source image */
+  srcW?: number;
+  /** the height to which to crop the source image */
+  srcH?: number;
+}
+
 /**
  * Blits a source image on to this image
  */
@@ -14,22 +31,7 @@ function blit<I extends JimpClass>(
     srcY = 0,
     srcW = src.bitmap.width,
     srcH = src.bitmap.height,
-  }: {
-    /** This image to blit on to the current image */
-    src: I;
-    /** the x position to blit the image */
-    x: number;
-    /** the y position to blit the image */
-    y: number;
-    /** the x position from which to crop the source image */
-    srcX?: number;
-    /** the y position from which to crop the source image */
-    srcY?: number;
-    /** the width to which to crop the source image */
-    srcW?: number;
-    /** the height to which to crop the source image */
-    srcH?: number;
-  },
+  }: BlitOptions<I>,
 ) {
   if (!("bitmap" in src)) {
     throw new Error("The source must be a Jimp image");