Struct assert_fs::NamedTempFile

pub struct NamedTempFile { /* fields omitted */ }

A potential file in the filesystem that is automatically deleted when it goes out of scope.

The NamedTempFile type creates a directory on the file system that is deleted once it goes out of scope. At construction, the NamedTempFile creates a new directory with a randomly generated name.

The constructor, [NamedTempFile::new(name)], creates directories in the location returned by std::env::temp_dir().

After creating a NamedTempFile, work with the file system by doing standard std::fs file system operations on its Path, which can be retrieved with NamedTempFile::path(). Once the NamedTempFile value is dropped, the parent directory will be deleted, along with the file. It is your responsibility to ensure that no further file system operations are attempted inside the temporary directory once it has been deleted.

Resource Leaking

Various platform-specific conditions may cause NamedTempFile to fail to delete the underlying directory. It's important to ensure that handles (like File and ReadDir) to the file inside the directory is dropped before the NamedTempFile goes out of scope. The NamedTempFile destructor will silently ignore any errors in deleting the directory; to instead handle errors call NamedTempFile::close().

Note that if the program exits before the NamedTempFile destructor is run, such as via std::process::exit(), by segfaulting, or by receiving a signal like SIGINT, then the temporary directory will not be deleted.

Examples

Create a temporary file.

use assert_fs::fixture::NamedTempFile;

let tmp_file = NamedTempFile::new("foo.rs").unwrap();

// Ensure deletion happens.
tmp_file.close().unwrap();

Methods

impl NamedTempFile

pub fn new<S>(name: S) -> Result<Self, FixtureError> where
    S: AsRef<OsStr>, 

Attempts to make a temporary file inside of env::temp_dir().

The file and parent directory will be automatically deleted once the returned NamedTempFile is destroyed.

Errors

If the parent directory can not be created, Err is returned.

Examples

use assert_fs::fixture::NamedTempFile;

let tmp_file = NamedTempFile::new("foo.rs").unwrap();

// Ensure deletion happens.
tmp_file.close().unwrap();

pub fn into_persist_if(self, yes: bool) -> Self

Conditionally persist the temporary file for debug purposes.

Note: this operation is not reversible, i.e. into_persist_if(false) is a no-op.

Examples

use assert_fs::fixture::NamedTempFile;

let tmp_file = NamedTempFile::new("foo.rs")
    .unwrap()
    .into_persist_if(std::env::var_os("TEST_PERSIST_FILES").is_some());

// Ensure deletion happens.
tmp_file.close().unwrap();

pub fn into_persist(self) -> Self

Persist the temporary file for debug purposes.

Note: this operation is not reversible, i.e. into_persist_if(false) is a no-op.

Examples

use assert_fs::fixture::NamedTempFile;

let tmp_file = NamedTempFile::new("foo.rs")
    .unwrap()
    .into_persist();

// Ensure deletion happens.
tmp_file.close().unwrap();

pub fn path(&self) -> &Path

Accesses the Path to the temporary file.

Examples

use assert_fs::fixture::NamedTempFile;

let tmp_file = NamedTempFile::new("foo.rs").unwrap();

println!("{}", tmp_file.path().display());

// Ensure deletion happens.
tmp_file.close().unwrap();

pub fn close(self) -> Result<(), FixtureError>

Closes and removes the temporary file and parent directory, returing a Result.

Although NamedTempFile removes the directory on drop, in the destructor any errors are ignored. To detect errors cleaning up the temporary directory, call close instead.

Errors

This function may return a variety of std::io::Errors that result from deleting the temporary file and parent directory, These errors may be platform specific.

Examples

use assert_fs::fixture::NamedTempFile;

let tmp_file = NamedTempFile::new("foo.rs").unwrap();

// Ensure deletion happens.
tmp_file.close().unwrap();

Trait Implementations

impl PathAssert for NamedTempFile

fn assert<I, P>(&self, pred: I) -> &Self where
    I: IntoPathPredicate<P>,
    P: Predicate<Path>, 

Assert the state of files within [TempDir].

impl FileTouch for NamedTempFile

fn touch(&self) -> Result<(), FixtureError>

Create an empty file at [ChildPath].

impl FileWriteBin for NamedTempFile

fn write_binary(&self, data: &[u8]) -> Result<(), FixtureError>

Write a binary file at [ChildPath].

impl FileWriteStr for NamedTempFile

fn write_str(&self, data: &str) -> Result<(), FixtureError>

Write a text file at [ChildPath].

impl FileWriteFile for NamedTempFile

fn write_file(&self, data: &Path) -> Result<(), FixtureError>

Write (copy) a file to [ChildPath].