Merge configs from parent directories

ci/integration.sh

@@ -71,25 +71,27 @@ function show_head {
     echo "Head commit of ${INTEGRATION}: $head"
 }
 
+tempdir=$(mktemp -d)
+
 case ${INTEGRATION} in
     cargo)
-        git clone --depth=1 https://github.com/rust-lang/${INTEGRATION}.git
-        cd ${INTEGRATION}
+        git clone --depth=1 https://github.com/rust-lang/${INTEGRATION}.git ${tempdir}
+        cd ${tempdir}
         show_head
         export CFG_DISABLE_CROSS_TESTS=1
         check_fmt_with_all_tests
         cd -
         ;;
     crater)
-        git clone --depth=1 https://github.com/rust-lang-nursery/${INTEGRATION}.git
-        cd ${INTEGRATION}
+        git clone --depth=1 https://github.com/rust-lang-nursery/${INTEGRATION}.git ${tempdir}
+        cd ${tempdir}
         show_head
         check_fmt_with_lib_tests
         cd -
         ;;
     *)
-        git clone --depth=1 https://github.com/rust-lang-nursery/${INTEGRATION}.git
-        cd ${INTEGRATION}
+        git clone --depth=1 https://github.com/rust-lang-nursery/${INTEGRATION}.git ${tempdir}
+        cd ${tempdir}
         show_head
         check_fmt_with_all_tests
         cd -

rustfmt-core/rustfmt-bin/src/bin/main.rs

@@ -425,7 +425,7 @@ fn format_string(input: String, opt: Opt) -> Result<i32> {
 
 enum FileConfig {
     Default,
-    Local(Config, Option<PathBuf>),
+    Local(Config, Option<Vec<PathBuf>>),
 }
 
 struct FileConfigPair<'a> {
@@ -457,9 +457,9 @@ impl<'a> Iterator for FileConfigPairIter<'a> {
         let config = if self.has_config_from_commandline {
             FileConfig::Default
         } else {
-            let (local_config, config_path) =
+            let (local_config, config_paths) =
                 load_config(Some(file.parent()?), Some(self.opt)).ok()?;
-            FileConfig::Local(local_config, config_path)
+            FileConfig::Local(local_config, config_paths)
         };
 
         Some(FileConfigPair { file, config })
@@ -483,11 +483,18 @@ fn format(opt: Opt) -> Result<i32> {
         return Err(format_err!("Error: `{}` is a directory", dir.display()));
     }
 
-    let (default_config, config_path) = load_config(None, Some(&opt))?;
+    let (default_config, config_paths) = load_config(None, Some(&opt))?;
 
     if opt.verbose {
-        if let Some(path) = config_path.as_ref() {
-            println!("Using rustfmt config file {}", path.display());
+        if let Some(paths) = config_paths.as_ref() {
+            println!(
+                "Using rustfmt config file(s) {}",
+                paths
+                    .into_iter()
+                    .map(|p| p.display().to_string())
+                    .collect::<Vec<_>>()
+                    .join(","),
+            );
         }
     }
 
@@ -496,7 +503,7 @@ fn format(opt: Opt) -> Result<i32> {
         verbosity: opt.verbosity(),
     };
 
-    let inputs = FileConfigPairIter::new(&opt, config_path.is_some()).collect::<Vec<_>>();
+    let inputs = FileConfigPairIter::new(&opt, config_paths.is_some()).collect::<Vec<_>>();
     let format_report = format_inputs(
         inputs.iter().map(|p| {
             (

rustfmt-core/rustfmt-lib/src/config.rs

@@ -170,6 +170,43 @@ impl PartialConfig {
 
         ::toml::to_string(&cloned).map_err(ToTomlError)
     }
+
+    pub fn from_toml_path(file_path: &Path) -> Result<PartialConfig, Error> {
+        let mut file = File::open(&file_path)?;
+        let mut toml = String::new();
+        file.read_to_string(&mut toml)?;
+        PartialConfig::from_toml(&toml).map_err(|err| Error::new(ErrorKind::InvalidData, err))
+    }
+
+    fn from_toml(toml: &str) -> Result<PartialConfig, String> {
+        let parsed: ::toml::Value = toml
+            .parse()
+            .map_err(|e| format!("Could not parse TOML: {}", e))?;
+        let mut err = String::new();
+        let table = parsed
+            .as_table()
+            .ok_or_else(|| String::from("Parsed config was not table"))?;
+        for key in table.keys() {
+            if !Config::is_valid_name(key) {
+                let msg = &format!("Warning: Unknown configuration option `{}`\n", key);
+                err.push_str(msg)
+            }
+        }
+        match parsed.try_into() {
+            Ok(parsed_config) => {
+                if !err.is_empty() {
+                    eprint!("{}", err);
+                }
+                Ok(parsed_config)
+            }
+            Err(e) => {
+                err.push_str("Error: Decoding config file failed:\n");
+                err.push_str(format!("{}\n", e).as_str());
+                err.push_str("Please check your config file.");
+                Err(err)
+            }
+        }
+    }
 }
 
 impl Config {
@@ -197,11 +234,8 @@ impl Config {
     /// Returns a `Config` if the config could be read and parsed from
     /// the file, otherwise errors.
     pub fn from_toml_path(file_path: &Path) -> Result<Config, Error> {
-        let mut file = File::open(&file_path)?;
-        let mut toml = String::new();
-        file.read_to_string(&mut toml)?;
-        Config::from_toml(&toml, file_path.parent().unwrap())
-            .map_err(|err| Error::new(ErrorKind::InvalidData, err))
+        let partial_config = PartialConfig::from_toml_path(file_path)?;
+        Ok(Config::default().fill_from_parsed_config(partial_config, file_path.parent().unwrap()))
     }
 
     /// Resolves the config for input in `dir`.
@@ -213,85 +247,77 @@ impl Config {
     ///
     /// Returns the `Config` to use, and the path of the project file if there was
     /// one.
-    pub fn from_resolved_toml_path(dir: &Path) -> Result<(Config, Option<PathBuf>), Error> {
+    pub fn from_resolved_toml_path(dir: &Path) -> Result<(Config, Option<Vec<PathBuf>>), Error> {
         /// Try to find a project file in the given directory and its parents.
         /// Returns the path of a the nearest project file if one exists,
         /// or `None` if no project file was found.
-        fn resolve_project_file(dir: &Path) -> Result<Option<PathBuf>, Error> {
+        fn resolve_project_files(dir: &Path) -> Result<Option<Vec<PathBuf>>, Error> {
             let mut current = if dir.is_relative() {
                 env::current_dir()?.join(dir)
             } else {
                 dir.to_path_buf()
             };
 
             current = dunce::canonicalize(current)?;
+            let mut paths = Vec::new();
 
             loop {
-                match get_toml_path(&current) {
-                    Ok(Some(path)) => return Ok(Some(path)),
-                    Err(e) => return Err(e),
-                    _ => (),
-                }
+                let current_toml_path = get_toml_path(&current)?;
+                paths.push(current_toml_path);
 
                 // If the current directory has no parent, we're done searching.
                 if !current.pop() {
                     break;
                 }
             }
 
+            // List of closest -> most distant rustfmt config from the current directory.
+            let config_paths: Option<Vec<_>> = paths.into_iter().filter(|p| p.is_some()).collect();
+            let has_paths = config_paths
+                .as_ref()
+                .map_or(false, |paths| !paths.is_empty());
+            if has_paths {
+                return Ok(config_paths);
+            }
+
             // If nothing was found, check in the home directory.
             if let Some(home_dir) = dirs::home_dir() {
                 if let Some(path) = get_toml_path(&home_dir)? {
-                    return Ok(Some(path));
+                    return Ok(Some(vec![path]));
                 }
             }
 
             // If none was found ther either, check in the user's configuration directory.
             if let Some(mut config_dir) = dirs::config_dir() {
                 config_dir.push("rustfmt");
                 if let Some(path) = get_toml_path(&config_dir)? {
-                    return Ok(Some(path));
+                    return Ok(Some(vec![path]));
                 }
             }
 
             Ok(None)
         }
 
-        match resolve_project_file(dir)? {
+        match resolve_project_files(dir)? {
             None => Ok((Config::default(), None)),
-            Some(path) => Config::from_toml_path(&path).map(|config| (config, Some(path))),
+            Some(paths) => {
+                let mut config = Config::default();
+                let mut used_paths = Vec::with_capacity(paths.len());
+                for path in paths.into_iter().rev() {
+                    let partial_config = PartialConfig::from_toml_path(&path)?;
+                    config = config.fill_from_parsed_config(partial_config, &path);
+                    used_paths.push(path);
+                }
+
+                Ok((config, Some(used_paths)))
+            }
         }
     }
 
     pub fn from_toml(toml: &str, dir: &Path) -> Result<Config, String> {
-        let parsed: ::toml::Value = toml
-            .parse()
-            .map_err(|e| format!("Could not parse TOML: {}", e))?;
-        let mut err = String::new();
-        let table = parsed
-            .as_table()
-            .ok_or_else(|| String::from("Parsed config was not table"))?;
-        for key in table.keys() {
-            if !Config::is_valid_name(key) {
-                let msg = &format!("Warning: Unknown configuration option `{}`\n", key);
-                err.push_str(msg)
-            }
-        }
-        match parsed.try_into() {
-            Ok(parsed_config) => {
-                if !err.is_empty() {
-                    eprint!("{}", err);
-                }
-                let config = Config::default().fill_from_parsed_config(parsed_config, dir);
-                Ok(config)
-            }
-            Err(e) => {
-                err.push_str("Error: Decoding config file failed:\n");
-                err.push_str(format!("{}\n", e).as_str());
-                err.push_str("Please check your config file.");
-                Err(err)
-            }
-        }
+        let partial_config = PartialConfig::from_toml(toml)?;
+        let config = Config::default().fill_from_parsed_config(partial_config, dir);
+        Ok(config)
     }
 }
 
@@ -300,14 +326,14 @@ impl Config {
 pub fn load_config<O: CliOptions>(
     file_path: Option<&Path>,
     options: Option<&O>,
-) -> Result<(Config, Option<PathBuf>), Error> {
+) -> Result<(Config, Option<Vec<PathBuf>>), Error> {
     let over_ride = match options {
         Some(opts) => config_path(opts)?,
         None => None,
     };
 
     let result = if let Some(over_ride) = over_ride {
-        Config::from_toml_path(over_ride.as_ref()).map(|p| (p, Some(over_ride.to_owned())))
+        Config::from_toml_path(over_ride.as_ref()).map(|p| (p, Some(vec![over_ride.to_owned()])))
     } else if let Some(file_path) = file_path {
         Config::from_resolved_toml_path(file_path)
     } else {
@@ -417,6 +443,42 @@ mod test {
         }
     }
 
+    struct TempFile {
+        path: PathBuf,
+    }
+
+    fn make_temp_file(file_name: &'static str, content: &'static str) -> TempFile {
+        use std::env::var;
+
+        // Used in the Rust build system.
+        let target_dir = var("RUSTFMT_TEST_DIR").map_or_else(|_| env::temp_dir(), PathBuf::from);
+        let path = target_dir.join(file_name);
+
+        fs::create_dir_all(path.parent().unwrap()).expect("couldn't create temp file");
+        let mut file = File::create(&path).expect("couldn't create temp file");
+        file.write_all(content.as_bytes())
+            .expect("couldn't write temp file");
+        TempFile { path }
+    }
+
+    impl Drop for TempFile {
+        fn drop(&mut self) {
+            use std::fs::remove_file;
+            remove_file(&self.path).expect("couldn't delete temp file");
+        }
+    }
+
+    struct NullOptions;
+
+    impl CliOptions for NullOptions {
+        fn apply_to(&self, _: &mut Config) {
+            unreachable!();
+        }
+        fn config_path(&self) -> Option<&Path> {
+            unreachable!();
+        }
+    }
+
     #[test]
     fn test_config_set() {
         let mut config = Config::default();
@@ -568,6 +630,44 @@ ignore = []
         assert_eq!(&toml, &default_config);
     }
 
+    #[test]
+    fn test_merged_config() {
+        match option_env!("CFG_RELEASE_CHANNEL") {
+            // this test requires nightly
+            None | Some("nightly") => {
+                let _outer_config = make_temp_file(
+                    "a/rustfmt.toml",
+                    r#"
+tab_spaces = 2
+fn_call_width = 50
+ignore = ["b/main.rs", "util.rs"]
+"#,
+                );
+
+                let inner_config = make_temp_file(
+                    "a/b/rustfmt.toml",
+                    r#"
+version = "two"
+tab_spaces = 3
+ignore = []
+"#,
+                );
+
+                let inner_dir = inner_config.path.parent().unwrap();
+                let (config, paths) = load_config::<NullOptions>(Some(inner_dir), None).unwrap();
+
+                assert_eq!(config.tab_spaces(), 3);
+                assert_eq!(config.fn_call_width(), 50);
+                assert_eq!(config.ignore().to_string(), r#"["main.rs"]"#);
+
+                let paths = paths.unwrap();
+                assert!(paths[0].ends_with("a/rustfmt.toml"));
+                assert!(paths[1].ends_with("a/b/rustfmt.toml"));
+            }
+            _ => (),
+        };
+    }
+
     mod unstable_features {
         use super::super::*;