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Overview

The tuist hash command provides utilities to debug the hashing logic used by features like binary caching and selective testing. It helps you understand how Tuist calculates hashes for your targets and dependencies.

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Usage

tuist hash [subcommand] [options]

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Subcommands

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tuist hash cache

Returns the hashes that will be used to persist binaries of the graph in its current state to the cache. 
tuist hash cache [options]

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tuist hash selective-testing

Returns the hashes that will be used to persist targets’ test results to select tests in future test runs. 
tuist hash selective-testing [options]

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Options (for hash cache)

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--path
string
default:"."
The path to the directory that contains the project whose targets will be cached.
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-p
string
Short form of --path.
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--configuration
string
The project configuration the cache binaries will be bound to (e.g., Debug, Release).
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-c
string
Short form of --configuration.

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Options (for hash selective-testing)

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--path
string
default:"."
The path to the directory that contains the project whose tests will run selectively.
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-p
string
Short form of --path.

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Examples

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Get cache hashes for current state

tuist hash cache
Displays the hashes for all targets in the project that will be used for binary caching.

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Get cache hashes for specific configuration

tuist hash cache --configuration Release
Shows the hashes that will be used when caching binaries with the Release configuration.

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Get selective testing hashes

tuist hash selective-testing
Displays the hashes used to track test results for selective test execution.

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Get hashes for specific project path

tuist hash cache --path path/to/project
Calculates hashes for targets in the specified project directory.

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Understanding hashing

Tuist’s hashing system is crucial for both binary caching and selective testing:

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Cache hashing

The cache hash for a target is calculated based on:
  1. Source files and their contents
  2. Build settings and configuration
  3. Dependencies and their hashes (cascading)
  4. Resources and other target inputs
When any of these change, the hash changes, indicating that the cached binary is no longer valid.

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Selective testing hashing

The selective testing hash is used to determine:
  1. Which tests need to run based on code changes
  2. Which test results can be reused from previous runs
  3. Dependencies between test targets and source code

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Debugging cache misses

Use tuist hash cache to debug why binaries aren’t being retrieved from cache:
  1. Run the command before and after changes
  2. Compare the hashes to identify which targets changed
  3. Investigate why unchanged targets show different hashes
Common causes of unexpected hash changes:
  • Generated files with timestamps
  • Environment-dependent build settings
  • Absolute paths in build settings
  • Dependency version updates

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Best practices

Verify hashing

Use tuist hash cache to verify that your cache configuration is working as expected.

Debug cache misses

Compare hashes before and after changes to understand cache invalidation.

Test selectivity

Use tuist hash selective-testing to debug selective test execution.

Configuration consistency

Ensure you use the same configuration when generating and hashing.