Dialyzer error

[Jarrod Moldrich]

Hi Kip,

As always, thanks for your work.

Found I was getting the cryptic dialyzer error for "No local return" in one of my functions. By divide and conquer I found the offending line:

browser_image = Image.stream!(image, strip_metadata: true, suffix: ".webp", buffer_size: 5_242_880)

I had a look at the typing information of the keyword list of image_write_options, and I noticed buffer-size was missing and that also the image_write_options union type included options that themselves were wrapped in a keyword list. If I'm reading it correctly – which I might not be – something like this would satisfy the typing:

browser_image = Image.stream!(image, [[strip_metadata: true], suffix: ".webp"])

... which is probably not what you intended. If I change the typing to add :buffer_size and unwrap the keyword options as below, the dialyzer error goes away. Is this maybe how the typing is supposed to be?

 @type image_write_options :: [
          {:buffer_size, integer()}
          | {:suffix, String.t()}
          | jpeg_write_option()
          | png_write_option()
          | tiff_write_option()
          | webp_write_option()
        ]

  @type jpeg_write_option :: {:quality, 1..100}
          | {:strip_metadata, boolean()}
          | {:icc_profile, Path.t()}
          | {:background, Image.pixel()}

  @type jpeg_write_options :: [ jpeg_write_option() ]

  @type png_write_option :: {:quality, 1..100}
          | {:strip_metadata, boolean()}
          | {:icc_profile, Path.t()}
          | {:background, Image.pixel()}

  @type png_write_options :: [ png_write_option() ]

  @type tiff_write_option :: {:quality, 1..100}
          | {:icc_profile, Path.t()}
          | {:background, Image.pixel()}

  @type tiff_write_options :: [ tiff_write_option() ]

  @type heif_write_option :: {:quality, 1..100}
          | {:background, Image.pixel()}
          | {:compression, compression()}

  @type heif_write_options :: [ heif_write_option() ]

  @type webp_write_option :: {:quality, 1..100}
          | {:icc_profile, Path.t()}
          | {:background, Image.pixel()}
          | {:strip_metadata, boolean()}

  @type webp_write_options :: [ webp_write_option() ]

[Kip Cole]

@jarrodmoldrich thanks for the report. Your are completely correct. I've been working on improving options and so the timing of your report is also very helpful. I've pushed ec3b08a which I think fixes this issue.

Would you consider trying it from GitHub directly and let me know? When you give the all-clear I will publish version 0.23.0.

The changelog entry now reads:

Bug Fixes

• Fix specs for Image.Options.Write. Thanks to @jarrodmoldrich. Closes #36.

Enhancements

• Image.Options.Write.validate_options/2 now validates options appropriate to each image type in order to make validation more robust.

• Adds :minimize_file_size option to Image.write/2 for JPEG and PNG files which if true will apply a range of techniques to minimize the size of the image file at the expense of time to save the image and potentially image quality.

[Jarrod Moldrich]

@kipcole9 Thanks for the prompt fix! I have confirmed that latest main works.