ImageLinter

Check image files and resources for Swift

Script allows

1. Checking size of vector(PDF) and rastor(PNG/JPEG) files
2. Catch unwanted raster from PDF or SVG (vector files)
3. Checking unused image from sources files
4. Search undefined images from resources
5. Comparing scaled images size
6. Checking duplicate images by name
7. Checking duplicate images by content (but binary identical)
8. Search empty and broken asset images
9. Analysis scales of images with dependency on platforms target
10. Checking the name of images with convensions or custom patterns apply filters

Accessibility

1. Possible analyse the sources (swift, Objective-C files) and resources (xcassets, Storyboard, xib files, images files)
2. Support xcassets and images files with @Xx notation
3. vector/rastor diffenition and you can limit use formats by PNG, JPG, PDF, SVG, etc formats
4. Support any use notation: SwiftUI, UIKit, SwiftGen, and custom Regex
5. You can ignore any images or sources use if need
6. Any settings for generation errors or warnings with different filters

Install

Swift Package Manager (SPM)

The Swift Package Manager is a tool for automating the distribution of Swift code and is integrated into the swift compiler. Imagelinter supports its use on supported platforms as plugin tool.

Once you have your Swift package set up, adding Imagelinter as a dependency is as easy as adding it to the dependencies value of your Package.swift. Then you need call from your target plugin like this:

    dependencies: [
        .Package(url: "https://github.com/ByteriX/Imagelinter.git", majorVersion: 2)
    ],
    targets: [
        .target(
            name: "YourTarget",
            plugins: [
                .plugin(name: "ImagelinterPlugin", package: "Imagelinter"),
            ]
        )
    ]
    

Swift script from Build Phases

1. Just copy ImageLinter.swift to project.
2. Exclude from "Build Phases" -> "Compile Sources"
3. Add to "Build Phases" run script:

${SRCROOT}/ImageLinter.swift

Settings:

You need to add a settings file named imagelinter.yaml or/and imagelinter.yml to a target or/and the root of the library dir of the package. imagesPath and sourcePath are calculated from dir of this package.

Supports more settings files with rewrite properties with priority: first a target then the root of library dir, first imagelinter.yaml then imagelinter.yml. If you want to have a custom path to settings file, you can use --settingsPath [path to your imagelinter.yaml or imagelinter.yml file] command line param from script call only on build phase. In the plugin this would be set to target dirrectory all time.

How to setting up your yaml file

isEnabled - turn on/off working of this plugin/script. Is boolean param with true \ false value. Default is true. Example:

isEnabled: true

relativeImagesPath (deprecated) please use array of path relativeImagesPaths. Now you can use jointly relativeImagesPaths. From 2.0 version will be removed. Example:

relativeImagesPath: /Sources/Images/Resource1
relativeImagesPaths:
  - /Sources/Images/Resource2
  - /Sources/Images/Resource3

relativeImagesPaths array of paths to directory that contains xcassets and images files of project. Example:

relativeImagesPaths:
  - /Sources/Images/Resource2
  - /Modules/Module1/Images
  - /Modules/Module2/Images

Please don't contents name of .xcassets or images files to path. Path should reference directory who content images files or xcassets. Examples: ⛔ How not to do it:

relativeImagesPaths:
  - /Resources/Images/Catalog.xcassets
  - /Resources/Images/Icon.png

✅ As it should be:

relativeImagesPaths:
  - /Resources/Images/

relativeSourcePath (deprecated) please use array of path relativeSourcePaths. Now you can use jointly relativeSourcePaths. From 2.0 version will be removed. Example:

relativeSourcePath: /Main/src
relativeSourcePaths:
  - /Module1/src
  - /Module2/src

relativeSourcePaths array of paths to directory that contains files with a source code of project which use images. Please don't contents name of files to path. Example:

relativeSourcePaths:
  - /Sources/
  - /Modules/Module1/Sources
  - /Modules/Module2/Sources

Please don't contents name of sources files to path. Path should reference directory who content sources files. Examples: ⛔ How not to do it:

relativeSourcePaths:
  - /Sources/View/ContentView.swift
  - /Sources/Utils.c

✅ As it should be:

relativeSourcePaths:
  - /Sources/

usingTypes - array of ways to use images from sources. You can use pre-installed case or/and make your regular expressions to match with your a way to use images.

cases:

swiftUI - when you use images from initializer Image. Example:

VStack {
    Image("picture")
}

uiKit - when you use images from initializer UIImage. Example:

let img = UIImage(named: "picture")

uiKitLiteral - when you use images from literal. Examples:

Image(uiImage: 🖼)  // SwiftUI
let uiKitPicture = #imageLiteral(resourceName: "picture")

swiftGen - when you use images from constants generated by xcodegen utilite. This option has parameter enumName - root name of images asset. Default is Asset.

Examples of use in settings:

usingTypes:
  - case: swiftGen # with default enumName
  - case: swiftGen # with custom enumName
    enumName: SpecialAsset
  - case: swiftGen # other enumName
    enumName: NewAsset

Examples of use in sources:

VStack { // SwiftUI:
    Asset.picture.image
}
let uiKitPicture = Asset.picture.uiImage
let img = UIImage(named: Asset.picture.name)

custom - setting up your regular expression to match with your a way to use images. This option has parameters: pattern - required parameter with a text of regular expression. isSwiftGen - addition parameter for understanding generated this image name fron SwiftGen or not. Default is false.

Examples of use in settings:

usingTypes:
  - case: custom
    pattern: "(.*)".image
  - case: custom
    pattern: "(.*)".uiImage

Examples of use in sources:

VStack { // SwiftUI:
    "picture".image
}
let uiKitPicture = "picture".uiImage

checkingNameTypes - array of ways to checking a image name used from the project. You can use pre-installed case or/and make your regular expressions to match with your a way to checking a image name. Every way works separated.

every case has standart options:

message - addition parameter text to show developer if checking fail. Has default value for every cases. filter - addition optional parameter text with filter query for selection images to checking. Default all images. If you want use custom filter query see [Filter Settings](Filter Settings) section.

cases:

firstUpperCase - Name should start with uppercase. camelCase - Camel case support only. sneak_case - Sneak case support only. kebab_case - Kebab case support only. custom - setting up your regular expression to match with your a way to checking a image name. Has first required parameter pattern with text of the regular expression.

usingTypes:
  - case: camelCase
    # for files has size 10Mb and less
    filter: <=10Mb 
  - case: firstUpperCase
    message: First case should be uppered
    # for rastor images has size 10Mb and less
    filter: rastor, <=10Mb 
  - case: custom
    pattern: ^[a-zA-Z][a-zA-Z0-9]*_icon$
    message: Camel case without folder and with suffix '_icon' for vector images with size 100px or less.
    filter: vecor, <=100px

ignoredUnusedImages - array of image names that don't need to parse for use from a source code. For example this could be the icon of Application. Example:

ignoredUnusedImages:
  - temp
  - AppIcon

ignoredUndefinedImages - array of image names that couldn't found in project but used from a source code. For example this could be examples code from SwiftDoc. Example:

ignoredUndefinedImages:
  - exampleImage
  - exampleIcon

rastorExtensions - array of extensions of images files who contains raster type of pictures. This files will processining linter as resource. Default contains png, jpg, jpeg. You can use any values, for example:

rastorExtensions:
  - jpeg
  - png
  - gif
  - bmp
  - tiff
  - heic
  - WebP

vectorExtensions - array of extensions of images files who contains vector type of pictures. This files will processining linter as resource. Default contains pdf, svg. You can use any values, for example:

vectorExtensions:
  - svg 
  - ai
  - eps
  - pdf
  - cdr

sourcesExtensions - array of extensions of source code files who contains using of pictures. This files will processining linter as sources. Default contains swift, mm, m. You can use any values, for example:

sourcesExtensions:
  - swift
  - mm
  - m
  - c 
  - cpp

resourcesExtensions - array of extensions of resources files who contains screen layout. This files should contains using of pictures and will processining linter as sources. Default contains storyboard, xib. You can use any values, for example:

sourcesExtensions:
  - storyboard
  - xib

isAllFilesErrorShowing - bool parameter: if it's true you will see all similar errors for each file, and not for each one image. If you wan't show double errors/warnings for all files of an image change this to false. Default is false.

isAllFilesErrorShowing: true

maxVectorFileSize - integer parameter: maximum file size in bytes of a using images with vector type. Default is 20 KByte.

maxVectorFileSize: 40_000 # it is 40 Kb.

maxVectorImageSize - maximum picture sizes for images with vector type. It contains width and height properties of picture size in pixels of images files. Default is 100x100px.

# matches maximum 200x300 px
maxVectorImageSize:
  width: 200
  height: 300

maxRastorFileSize - integer parameter: maximum file size in bytes of a using images with rastor type. Default is 200 KByte.

maxRastorFileSize: 1_048_576 # it is 1 Mb.

maxRastorImageSize - maximum picture sizes for images with rastor type. It contains width and height properties of picture size in pixels of images files. Default is 1000x1000px.

# matches maximum 1024x1024 px
maxRastorImageSize:
  width: 1024
  height: 1024

isCheckingFileSize - bool parameter: The true value execute the file size checking of vector and rastor images with parameters maxVectorFileSize and maxRastorFileSize. If it's false params maxVectorFileSize and maxRastorFileSize will ignored. Default is true.

isCheckingFileSize: true

isCheckingImageSize - bool parameter: The true value execute the picture sizes checking of vector and rastor images with parameters maxVectorImageSize and maxRastorImageSize. If it's false params maxVectorImageSize and maxRastorImageSize will ignored. Default is true.

isCheckingImageSize: true

isCheckingPdfVector - bool parameter: The true value execute checking PDF files to contains vector picture only. Default is true.

isCheckingPdfVector: true

isCheckingSvgVector - bool parameter: The true value execute checking SVG files to contains vector picture only. Default is true.

isCheckingSvgVector: true

isCheckingScaleSize - bool parameter: The true value execute checking a image set to complaince all size in a set. For example the image set with name yourImageSet has images: yourImageSet.png (100x100 px), yourImageSet@2x.png (200x200 px), yourImageSet@3x.png (300x300 px). Sizes of yourImageSet check successfull. But if an one image has other size (for example yourImageSet@2x.png (201x202 px)) this test will fail. Default is true.

isCheckingScaleSize: true

isCheckingDuplicatedByName - bool parameter: The true value execute checking image sets to using unique name. Both Assets catalogs and individual images are considered as a common namespace. If you use duplicated name of common namespace you can see error. Default is true.

isCheckingDuplicatedByName: true

isCheckingDuplicatedByContent - bool parameter: The true value execute checking image sets to using unique content. Both Assets catalogs and individual images are considered as a common space. If you use duplicated files content (binary identical) of common space you can see error. Default is true.

isCheckingDuplicatedByContent: true

targetPlatforms - array of platform to use checking. Default contains iOS only. You can use iOS, iPadOS, macOS, tvOS, visionOS, watchOS.

targetPlatforms:
  - iOS
  - iPadOS
  - macOS

Filter Settings

In yaml settings may used filter string value for execute query of images with conditions, described according to the following diagram:

[image type], [condition] [value of size] [multiplier for value] [messure of size], etc

You can use a comma or a vertical bar to make a logical and/or in statement for any number of expressions:

[query1],[query2]|[query3]|[query4], [query5] | [query6]

Table of expressions:

Expression	Description	Variants	Example of using
,	Logical and with spaces or not	, ,	vector , >= 3Mpx
|	Logical or with spaces or not. It has a lower priority than logical and	| |	vector , >= 3Mpx
image type	Type of content from image	undefined, rastor, vector, mixed	vector
condition:	condition for comparing the current value of the size with the value following it.	>, =>, >=, <, =<, <=, =, ==	>= 2Kpx
=	current value equal to given value.	=, ==	== 2Kpx
>	current value more or equal to given value.	>, >=, =>	=> 2000b
<	current value less or equal to given value.	<, <=, =<	<= 10Mb
value of size	Integer given value of condition for comparing.	0, 400, 99999, and more	<100 Kpx
multiplier for value:	multiplier for given value for short designation.	k, K, m, M	>3 Mpx
k	x 1000 for pixels. x 1024 for bytes.	k, K	= 3 kB
m	x 1000 0000 for pixels. x 1024 x 1024 for bytes.	m, M	= 5 Mpx
messure of size:	Measurement for comparision of values.	PX, px, Px, B, b	>6 MB
px	Measurement in pixels for a width x height image size.	PX, px, Px	> 4 kPX
B	Measurement in bytes for a file size.	B, b	> 4 kB

Example of filter settings:

usingTypes:
  - case: camelCase
    # for vecor images with size 10 Mega bytes and less or rastor images with size width x height = 25000 and more
    filter: vector, <=10Mb | rastor, > 25kPx

Example of Settings file format

isEnabled: true
relativeImagesPath: /Sources/Images/Resources
relativeImagesPaths:
  - /Module1/res
  - /Module2/res
relativeSourcePath: /Sources/Code
relativeSourcePaths:
  - /Module1/src
  - /Module2/src
usingTypes:
  - case: uiKit
  - case: uiKitLiteral
  - case: swiftUI
  - case: swiftGen
    enumName: Asset
  - case: custom
    pattern: "(.*)".name
    isSwiftGen: true
  - case: custom
    pattern: "(.*)".image
checkingNameTypes:
  - case: camelCase
  - case: firstUpperCase
    message: First case should be uppered
  - case: custom
    pattern: ^[a-zA-Z][a-zA-Z0-9]*_icon$
    message: Camel case without folder and with suffix '_icon'
ignoredUnusedImages:
  - temp
ignoredUndefinedImages:
  - temp
rastorExtensions:
  - png
  - jpg
  - jpeg
vectorExtensions:
  - pdf
  - svg
sourcesExtensions:
  - swift
  - mm
resourcesExtensions:
  - storyboard
  - xib
isAllFilesErrorShowing: false
maxVectorFileSize: 10000
maxVectorImageSize:
  width: 100
  height: 100
maxRastorFileSize: 300000
maxRastorImageSize:
  width: 300
  height: 300
isCheckingFileSize: true
isCheckingImageSize: true
isCheckingPdfVector: true
isCheckingSvgVector: true
isCheckingScaleSize: true
isCheckingDuplicatedByName: true
isCheckingDuplicatedByContent: true
targetPlatforms:
  - iOS
  - iPadOS
  - macOS
  - tvOS
  - visionOS
  - watchOS

Example

You can review