feat: add sharp trim feature

Author: pmb0

Diff for: README.md

@@ -264,6 +264,7 @@ Currently the following transformations can be applied to images:
 | format | `f` | Output image format. Valid values: every valid [sharp output format string](https://sharp.pixelplumbing.com/api-output#toformat), i.e. `jpeg`, `gif`, `webp` or `raw`. |
 | progressive | `p` | Only available for jpeg and png formats. Enable progressive scan by passing `true`. |
 | crop | `c` | Setting crop to `true` enables the [sharp cropping feature](https://sharp.pixelplumbing.com/api-resize#crop). Note: Both `width` and `height` params are neccessary for crop to work. Default is `false`. |
+| trim | `t` | Setting trim to `true` enables the [sharp trim feature](https://sharp.pixelplumbing.com/api-resize#trim). |
 | gravity | `g` | When the crop option is activated you can specify the gravity of the cropping. Possible attributes of the optional `gravity` are `north`, `northeast`, `east`, `southeast`, `south`, `southwest`, `west`, `northwest`, `center` and `centre`. Default is `center`. |
 
 # License

Diff for: src/interfaces.ts

@@ -28,6 +28,7 @@ export enum QueryParams {
   format = 'f',
   progressive = 'p',
   crop = 'c',
+  trim = 't',
   gravity = 'g',
 }
 

Diff for: src/resize.dto.ts

@@ -54,6 +54,10 @@ export class ResizeDto {
   @IsBoolean()
   public crop: boolean = false
 
+  @Transform((value) => value === 'true')
+  @IsBoolean()
+  public trim: boolean = false
+
   @IsIn([
     'north',
     'northeast',

Diff for: src/transformer.service.ts

@@ -76,6 +76,10 @@ export class Transformer {
       options.format = (await transformer.metadata()).format as format
     }
 
+    if (options.trim) {
+      transformer.trim()
+    }
+
     if (options.crop) {
       const [cropWidth, cropHeight] = this.getCropDimensions(
         this.cropMaxSize,