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Dextrose is a testing library that enables the screen shots of components across all react-native platforms

This has been made possible using fructose to load components.

iOS loading in components and taking screenshots

Get an overview of your components across devices before you merge using the html report



Dextrose's purpose is to iterate through all the bundled components defined by showcases and take a screenshot of each.

The .showcase file is a description of how a component should be rendered. Showcase files came around because originally fructose consumed storybook files. This eventually resulted in numerous issues so we created an abstraction layer which decouples components from storybook. You can see a working example of how showcase to storybook works here.


react-native-showcase-loader can be used to dynamically generate a component file with all your defined components.


  • Images of components across native platforms
  • Images of components at specified breakpoints across web
  • Upload component images to specified s3 Bucket
  • Html presentation of images across platforms


Dextrose supports the following commands:


The Dextrose run command can be run with the following commands:

dextrose run --config, -c -path/to/config

    --config, -c -path/to/config

    --snapshotWait, -t
        Ms to wait between loading a component and taking the snap

    --loglevel, -l
        default is set to info, able to set level to verbose

Example config for platforms


    module.exports = {
        snapPath: path.join(__dirname, '../snaps'),
        platformName: "iOS",
        ignoredShowcases: ["IGNORE"]


    module.exports = {
        snapPath: path.join(__dirname, '../snaps'),
        platformName: "web",
        breakpoints:[500, 1000],
        ignoredShowcases: ["IGNORE"]

The Dextrose upload command can be run with the following commands to push component images to s3:

dextrose upload snapshotDir --bucket bucketname --key commit_hash

    --bucket, -b
        the name of the s3 bucket

    --key, -k
        the name of the key in the bucket

    --region, -r
        the aws region

The Dextrose generate-html command can be run with the following commands to generate component presentation:

dextrose generate-html --upload --bucket bucketname --key commit-hash

    --upload, -u
        using this will attempt to upload the html file to s3

    --bucket, -b
        the name of the s3 bucket

    --key, -k
        the name of the key in the bucket

    --region, -r
        the aws region

Running the example

To run the the example Pull the repo

  • Run yarn in the Dextrose folder
  • Run yarn in the snapshots folder (the snapshots folder is an example of how you would consume dextrose)
  • Run ./run-(ios | android | web).sh

note: please make sure you have an (emulator | simulator), and a packager running.

Future ideas

  • Comparison of images
  • Specify device orientation


React Native Snapshot Tool for Ios, Android & Web

Dextrose Info

⭐ Stars 24
🔗 Source Code
🕒 Last Update 2 years ago
🕒 Created 5 years ago
🐞 Open Issues 1
➗ Star-Issue Ratio 24
😎 Author NewsUKArchive