feat: Add an exists method to FileSystem #271
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This change adds an `exists` method to the `FileSystem` class, along with implementations for POSIX and Windows. The POSIX implementation uses `lstat` to check for the existence of a file system object. The Windows implementation uses `CreateFile`. Tests have been added to cover files, directories, links (including broken ones), and non-existent paths. I was unable to run the tests locally due to issues with the test environment, so I am relying on the CI to validate these changes.
aam
reviewed
Aug 15, 2025
| /// If `path` is a symbolic link, `exists` returns `false` if the link is | ||
| /// broken (i.e. the target of the link does not exist). | ||
| /// | ||
| /// On Windows, calling `exists` on a named pipe may cause the server to close |
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This sounds unexpected: it is surprising that exists can cause change to any state.
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exists call CreateFile, which opens the file. dart:io (sometimes) has the same behavior (and so does Python, Rust, etc.)
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I was thinking about making exists not follow the symlink so that it doesn't need to open the file. But that does against the current behavior of dart:io (and Python and Rust...)
aam
approved these changes
Aug 15, 2025
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