Allow reading patterns from stdin (#301)

Author: Byron

git-path/src/spec.rs

@@ -1,39 +1,41 @@
 use crate::Spec;
 use bstr::{BStr, ByteSlice, ByteVec};
 use std::ffi::OsStr;
-use std::str::FromStr;
 
 impl std::convert::TryFrom<&OsStr> for Spec {
     type Error = crate::Utf8Error;
 
     fn try_from(value: &OsStr) -> Result<Self, Self::Error> {
-        crate::os_str_into_bstr(value).map(|value| Spec(value.into()))
+        crate::os_str_into_bstr(value).map(|value| {
+            assert_valid_hack(value);
+            Spec(value.into())
+        })
     }
 }
 
-impl FromStr for Spec {
-    type Err = std::convert::Infallible;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        Ok(Spec(s.into()))
-    }
+fn assert_valid_hack(input: &BStr) {
+    assert!(!input.contains_str(b"/../"));
+    assert!(!input.contains_str(b"/./"));
+    assert!(!input.starts_with_str(b"../"));
+    assert!(!input.starts_with_str(b"./"));
+    assert!(!input.starts_with_str(b"/"));
 }
 
 impl Spec {
+    /// Parse `input` into a `Spec` or `None` if it could not be parsed
+    // TODO: tests, actual implementation probably via `git-pathspec` to make use of the crate after all.
+    pub fn from_bytes(input: &BStr) -> Option<Self> {
+        assert_valid_hack(input);
+        Spec(input.into()).into()
+    }
     /// Return all paths described by this path spec, using slashes on all platforms.
     pub fn items(&self) -> impl Iterator<Item = &BStr> {
         std::iter::once(self.0.as_bstr())
     }
     /// Adjust this path specification according to the given `prefix`, which may be empty to indicate we are the at work-tree root.
     // TODO: this is a hack, needs test and time to do according to spec. This is just a minimum version to have -something-.
     pub fn apply_prefix(&mut self, prefix: &std::path::Path) -> &Self {
-        assert!(!self.0.contains_str(b"/../"));
-        assert!(!self.0.contains_str(b"/./"));
-        assert!(!self.0.starts_with_str(b"../"));
-        assert!(!self.0.starts_with_str(b"./"));
-        assert!(!self.0.starts_with_str(b"/"));
         // many more things we can't handle. `Path` never ends with trailing path separator.
-
         let prefix = crate::into_bstr(prefix);
         if !prefix.is_empty() {
             let mut prefix = crate::to_unix_separators_on_windows(prefix);

gitoxide-core/src/repository/exclude.rs

@@ -7,24 +7,22 @@ use git_repository::prelude::FindExt;
 
 pub mod query {
     use crate::OutputFormat;
-    use git_repository as git;
     use std::ffi::OsString;
 
     pub struct Options {
         pub format: OutputFormat,
-        pub pathspecs: Vec<git::path::Spec>,
         pub overrides: Vec<OsString>,
         pub show_ignore_patterns: bool,
     }
 }
 
 pub fn query(
     repo: git::Repository,
+    pathspecs: impl Iterator<Item = git::path::Spec>,
     mut out: impl io::Write,
     query::Options {
         overrides,
         format,
-        pathspecs,
         show_ignore_patterns,
     }: query::Options,
 ) -> anyhow::Result<()> {

src/plumbing/main.rs

@@ -9,6 +9,7 @@ use std::{
 
 use anyhow::Result;
 use clap::Parser;
+use git_repository::bstr::io::BufReadExt;
 use gitoxide_core as core;
 use gitoxide_core::pack::verify;
 
@@ -206,12 +207,23 @@ pub fn main() -> Result<()> {
                         progress_keep_open,
                         None,
                         move |_progress, out, _err| {
+                            use git::bstr::ByteSlice;
                             core::repository::exclude::query(
                                 repository.into(),
+                                if pathspecs.is_empty() {
+                                    Box::new(
+                                        stdin_or_bail()?
+                                            .byte_lines()
+                                            .filter_map(Result::ok)
+                                            .map(|line| git::path::Spec::from_bytes(line.as_bstr()))
+                                            .flatten(),
+                                    ) as Box<dyn Iterator<Item = git::path::Spec>>
+                                } else {
+                                    Box::new(pathspecs.into_iter())
+                                },
                                 out,
                                 core::repository::exclude::query::Options {
                                     format,
-                                    pathspecs,
                                     show_ignore_patterns,
                                     overrides: patterns,
                                 },
@@ -341,16 +353,7 @@ pub fn main() -> Result<()> {
                     progress_keep_open,
                     core::pack::create::PROGRESS_RANGE,
                     move |progress, out, _err| {
-                        let input = if has_tips {
-                            None
-                        } else {
-                            if atty::is(atty::Stream::Stdin) {
-                                anyhow::bail!(
-                                    "Refusing to read from standard input as no path is given, but it's a terminal."
-                                )
-                            }
-                            Some(BufReader::new(stdin()))
-                        };
+                        let input = if has_tips { None } else { stdin_or_bail()?.into() };
                         let repository = repository.unwrap_or_else(|| PathBuf::from("."));
                         let context = core::pack::create::Context {
                             thread_limit,
@@ -641,6 +644,13 @@ pub fn main() -> Result<()> {
     Ok(())
 }
 
+fn stdin_or_bail() -> anyhow::Result<std::io::BufReader<std::io::Stdin>> {
+    if atty::is(atty::Stream::Stdin) {
+        anyhow::bail!("Refusing to read from standard input while a terminal is connected")
+    }
+    Ok(BufReader::new(stdin()))
+}
+
 fn verify_mode(decode: bool, re_encode: bool) -> verify::Mode {
     match (decode, re_encode) {
         (true, false) => verify::Mode::HashCrc32Decode,

src/plumbing/options.rs

@@ -395,7 +395,7 @@ pub mod repo {
                 /// Useful for undoing previous patterns using the '!' prefix.
                 #[clap(long, short = 'p')]
                 patterns: Vec<OsString>,
-                /// The git path specifications to check for exclusion.
+                /// The git path specifications to check for exclusion, or unset to read from stdin one per line.
                 #[clap(parse(try_from_os_str = std::convert::TryFrom::try_from))]
                 pathspecs: Vec<git::path::Spec>,
             },