Struct Watch 

#[non_exhaustive]
pub struct Watch {
    pub shell_commands: Vec<String>,
    pub cargo_commands: Vec<String>,
    pub watch_paths: Vec<PathBuf>,
    pub exclude_paths: Vec<PathBuf>,
    pub workspace_exclude_paths: Vec<PathBuf>,
    pub debounce: Duration,
    /* private fields */
}

Watches over your project’s source code, relaunching a given command when changes are detected.

Use Watch::lock to obtain a WatchLock that can be shared with external code (e.g. an HTTP server) to coordinate reads with ongoing rebuilds.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

shell_commands: Vec<String>

Shell command(s) to execute on changes.

cargo_commands: Vec<String>

Cargo command(s) to execute on changes.

The default is [ check ]

watch_paths: Vec<PathBuf>

Watch specific file(s) or folder(s).

The default is the workspace root.

exclude_paths: Vec<PathBuf>

Paths or glob patterns that will be excluded.

Relative values are resolved from the current working directory.

workspace_exclude_paths: Vec<PathBuf>

Paths or glob patterns, relative to the workspace root, that will be excluded.

debounce: Duration

Quiet period after the last detected change before the command is (re)started. If another change arrives while a build is running the build is cancelled and the timer resets, so only the latest state is ever built.

The default is 1 second.

Implementations

impl Watch

pub fn watch_path(self, path: impl AsRef<Path>) -> Self

Add a path to watch for changes.

pub fn watch_paths( self, paths: impl IntoIterator<Item = impl AsRef<Path>>, ) -> Self

Add multiple paths to watch for changes.

pub fn exclude_path(self, path: impl AsRef<Path>) -> Self

Add a path that will be ignored if changes are detected.

pub fn exclude_paths( self, paths: impl IntoIterator<Item = impl AsRef<Path>>, ) -> Self

Add multiple paths that will be ignored if changes are detected.

pub fn exclude_workspace_path(self, path: impl AsRef<Path>) -> Self

Add a path, relative to the workspace, that will be ignored if changes are detected.

pub fn exclude_workspace_paths( self, paths: impl IntoIterator<Item = impl AsRef<Path>>, ) -> Self

Add multiple paths, relative to the workspace, that will be ignored if changes are detected.

pub fn lock(&self) -> WatchLock

Return the shared lock used by this watcher.

Clone and share this lock with external code (e.g. HTTP handlers) to coordinate with watch-driven command execution.

Lock lifecycle

run acquires the write lock immediately when it is called — before the first command is even spawned. Any code that calls WatchLock::acquire will therefore block until the first build completes. This is intentional: it prevents readers from observing an empty or incomplete dist directory before the initial build has finished. The write lock is then re-acquired on every subsequent rebuild and released once the command sequence succeeds.

pub fn debounce(self, duration: Duration) -> Self

Set the debounce quiet period.

The command will not start (or restart) until no change has been detected for this duration. The default is 1 second.

pub fn run(self, commands: impl Into<CommandList>) -> Result<()>

Run the given command, monitor the watched paths and relaunch the command when changes are detected.

The command starts immediately. If a change is detected while it is running, the command is cancelled and the debounce timer resets; the command only restarts once the source tree has been quiet for the configured debounce duration.

Workspace’s target directory and hidden paths are excluded by default.

Trait Implementations

impl Args for Watch

fn group_id() -> Option<Id>

Report the ArgGroup::id for this set of arguments

fn augment_args<'b>(__clap_app: Command) -> Command

Append to Command so it can instantiate Self via FromArgMatches::from_arg_matches_mut

fn augment_args_for_update<'b>(__clap_app: Command) -> Command

Append to Command so it can instantiate self via FromArgMatches::update_from_arg_matches_mut

impl Clone for Watch

fn clone(&self) -> Watch

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl CommandFactory for Watch

fn command<'b>() -> Command

Build a Command that can instantiate Self.

fn command_for_update<'b>() -> Command

Build a Command that can update self.

impl Debug for Watch

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Watch

fn default() -> Watch

Returns the “default value” for a type.

impl FromArgMatches for Watch

fn from_arg_matches(__clap_arg_matches: &ArgMatches) -> Result<Self, Error>

Instantiate Self from ArgMatches, parsing the arguments as needed.

fn from_arg_matches_mut( __clap_arg_matches: &mut ArgMatches, ) -> Result<Self, Error>

Instantiate Self from ArgMatches, parsing the arguments as needed.

fn update_from_arg_matches( &mut self, __clap_arg_matches: &ArgMatches, ) -> Result<(), Error>

Assign values from ArgMatches to self.

fn update_from_arg_matches_mut( &mut self, __clap_arg_matches: &mut ArgMatches, ) -> Result<(), Error>

Assign values from ArgMatches to self.

impl Parser for Watch

fn parse() -> Self

Parse from std::env::args_os(), exit on error.

fn try_parse() -> Result<Self, Error>

Parse from std::env::args_os(), return Err on error.

fn parse_from<I, T>(itr: I) -> Self

where I: IntoIterator<Item = T>, T: Into<OsString> + Clone,

Parse from iterator, exit on error.

fn try_parse_from<I, T>(itr: I) -> Result<Self, Error>

where I: IntoIterator<Item = T>, T: Into<OsString> + Clone,

Parse from iterator, return Err on error.

fn update_from<I, T>(&mut self, itr: I)

where I: IntoIterator<Item = T>, T: Into<OsString> + Clone,

Update from iterator, exit on error.

fn try_update_from<I, T>(&mut self, itr: I) -> Result<(), Error>

where I: IntoIterator<Item = T>, T: Into<OsString> + Clone,

Update from iterator, return Err on error.