feat: parse the exec field

Author: wiiznokes

.vscode/settings.json

@@ -19,3 +19,4 @@ strsim = "0.11.1"
 thiserror = "1"
 xdg = "2.4.0"
 log = "0.4.21"
+

Cargo.toml

@@ -3,7 +3,7 @@ use std::path::Path;
 use freedesktop_desktop_entry::DesktopEntry;
 
 fn main() {
-    let path = Path::new("tests/org.mozilla.firefox.desktop");
+    let path = Path::new("tests_entries/org.mozilla.firefox.desktop");
     let locales = &["fr_FR", "en", "it"];
 
     // if let Ok(bytes) = fs::read_to_string(path) {

examples/specific_file.rs

@@ -0,0 +1,260 @@
+// Copyright 2021 System76 <[email protected]>
+// SPDX-License-Identifier: MPL-2.0
+
+use crate::DesktopEntry;
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum ExecError {
+    #[error("{0}")]
+    WrongFormat(String),
+
+    #[error("Exec field is empty")]
+    ExecFieldIsEmpty,
+
+    #[error("Exec key was not found")]
+    ExecFieldNotFound,
+}
+
+impl<'a> DesktopEntry<'a> {
+    pub fn parse_exec(&self) -> Result<Vec<String>, ExecError> {
+        self.get_args(self.exec(), &[], &[] as &[&str])
+    }
+
+    /// Macros like `%f` (cf [.desktop spec](https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html#exec-variables)) will be subtitued using the `uris` parameter.
+    pub fn parse_exec_with_uris<L>(
+        &self,
+        uris: &[&'a str],
+        locales: &[L],
+    ) -> Result<Vec<String>, ExecError>
+    where
+        L: AsRef<str>,
+    {
+        self.get_args(self.exec(), uris, locales)
+    }
+
+    pub fn parse_exec_action(&self, action_name: &str) -> Result<Vec<String>, ExecError> {
+        self.get_args(self.action_exec(action_name), &[], &[] as &[&str])
+    }
+
+    pub fn parse_exec_action_with_uris<L>(
+        &self,
+        action_name: &str,
+        uris: &[&'a str],
+        locales: &[L],
+    ) -> Result<Vec<String>, ExecError>
+    where
+        L: AsRef<str>,
+    {
+        self.get_args(self.action_exec(action_name), uris, locales)
+    }
+
+    fn get_args<L>(
+        &'a self,
+        exec: Option<&'a str>,
+        uris: &[&'a str],
+        locales: &[L],
+    ) -> Result<Vec<String>, ExecError>
+    where
+        L: AsRef<str>,
+    {
+        let Some(exec) = exec else {
+            return Err(ExecError::ExecFieldNotFound);
+        };
+
+        if exec.contains('=') {
+            return Err(ExecError::WrongFormat("equal sign detected".into()));
+        }
+
+        let exec = if let Some(without_prefix) = exec.strip_prefix('\"') {
+            without_prefix
+                .strip_suffix('\"')
+                .ok_or(ExecError::WrongFormat("unmatched quote".into()))?
+        } else {
+            exec
+        };
+
+        let mut args: Vec<String> = Vec::new();
+
+        for arg in exec.split_ascii_whitespace() {
+            match ArgOrFieldCode::try_from(arg) {
+                Ok(arg) => match arg {
+                    ArgOrFieldCode::SingleFileName | ArgOrFieldCode::SingleUrl => {
+                        if let Some(arg) = uris.first() {
+                            args.push(arg.to_string());
+                        }
+                    }
+                    ArgOrFieldCode::FileList | ArgOrFieldCode::UrlList => {
+                        uris.iter().for_each(|uri| args.push(uri.to_string()));
+                    }
+                    ArgOrFieldCode::IconKey => {
+                        if let Some(icon) = self.icon() {
+                            args.push(icon.to_string());
+                        }
+                    }
+                    ArgOrFieldCode::TranslatedName => {
+                        if let Some(name) = self.name(locales) {
+                            args.push(name.to_string());
+                        }
+                    }
+                    ArgOrFieldCode::DesktopFileLocation => {
+                        args.push(self.path.to_string_lossy().to_string());
+                    }
+                    ArgOrFieldCode::Arg(arg) => {
+                        args.push(arg.to_string());
+                    }
+                },
+                Err(e) => {
+                    log::error!("{}", e);
+                }
+            }
+        }
+
+        if args.is_empty() {
+            return Err(ExecError::ExecFieldIsEmpty);
+        }
+
+        Ok(args)
+    }
+}
+
+// either a command line argument or a field-code as described
+// in https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html#exec-variables
+enum ArgOrFieldCode<'a> {
+    SingleFileName,
+    FileList,
+    SingleUrl,
+    UrlList,
+    IconKey,
+    TranslatedName,
+    DesktopFileLocation,
+    Arg(&'a str),
+}
+
+#[derive(Debug, Error)]
+enum ExecErrorInternal<'a> {
+    #[error("Unknown field code: '{0}'")]
+    UnknownFieldCode(&'a str),
+
+    #[error("Deprecated field code: '{0}'")]
+    DeprecatedFieldCode(&'a str),
+}
+
+impl<'a> TryFrom<&'a str> for ArgOrFieldCode<'a> {
+    type Error = ExecErrorInternal<'a>;
+
+    // todo: handle escaping
+    fn try_from(value: &'a str) -> Result<Self, Self::Error> {
+        match value {
+            "%f" => Ok(ArgOrFieldCode::SingleFileName),
+            "%F" => Ok(ArgOrFieldCode::FileList),
+            "%u" => Ok(ArgOrFieldCode::SingleUrl),
+            "%U" => Ok(ArgOrFieldCode::UrlList),
+            "%i" => Ok(ArgOrFieldCode::IconKey),
+            "%c" => Ok(ArgOrFieldCode::TranslatedName),
+            "%k" => Ok(ArgOrFieldCode::DesktopFileLocation),
+            "%d" | "%D" | "%n" | "%N" | "%v" | "%m" => {
+                Err(ExecErrorInternal::DeprecatedFieldCode(value))
+            }
+            other if other.starts_with('%') => Err(ExecErrorInternal::UnknownFieldCode(other)),
+            other => Ok(ArgOrFieldCode::Arg(other)),
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+
+    use std::path::PathBuf;
+
+    use crate::{get_languages_from_env, DesktopEntry};
+
+    use super::ExecError;
+
+    #[test]
+    fn should_return_unmatched_quote_error() {
+        let path = PathBuf::from("tests_entries/exec/unmatched-quotes.desktop");
+        let locales = get_languages_from_env();
+        let de = DesktopEntry::from_path(path, Some(&locales)).unwrap();
+        let result = de.parse_exec_with_uris(&[], &locales);
+
+        assert!(matches!(result.unwrap_err(), ExecError::WrongFormat(..)));
+    }
+
+    #[test]
+    fn should_fail_if_exec_string_is_empty() {
+        let path = PathBuf::from("tests_entries/exec/empty-exec.desktop");
+        let locales = get_languages_from_env();
+        let de = DesktopEntry::from_path(path, Some(&locales)).unwrap();
+        let result = de.parse_exec_with_uris(&[], &locales);
+
+        assert!(matches!(result.unwrap_err(), ExecError::ExecFieldIsEmpty));
+    }
+
+    #[test]
+    fn should_exec_simple_command() {
+        let path = PathBuf::from("tests_entries/exec/alacritty-simple.desktop");
+        let locales = get_languages_from_env();
+        let de = DesktopEntry::from_path(path, Some(&locales)).unwrap();
+        let result = de.parse_exec_with_uris(&[], &locales);
+
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn should_exec_complex_command() {
+        let path = PathBuf::from("tests_entries/exec/non-terminal-cmd.desktop");
+        let locales = get_languages_from_env();
+        let de = DesktopEntry::from_path(path, Some(&locales)).unwrap();
+        let result = de.parse_exec_with_uris(&[], &locales);
+
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn should_exec_terminal_command() {
+        let path = PathBuf::from("tests_entries/exec/non-terminal-cmd.desktop");
+        let locales = get_languages_from_env();
+        let de = DesktopEntry::from_path(path, Some(&locales)).unwrap();
+        let result = de.parse_exec_with_uris(&[], &locales);
+
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    #[ignore = "Needs a desktop environment with nvim installed, run locally only"]
+    fn should_parse_exec_with_field_codes() {
+        let path = PathBuf::from("/usr/share/applications/nvim.desktop");
+        let locales = get_languages_from_env();
+        let de = DesktopEntry::from_path(path, Some(&locales)).unwrap();
+        let result = de.parse_exec_with_uris(&["src/lib.rs"], &locales);
+
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    #[ignore = "Needs a desktop environment with gnome Books installed, run locally only"]
+    fn should_parse_exec_with_dbus() {
+        let path = PathBuf::from("/usr/share/applications/org.gnome.Books.desktop");
+        let locales = get_languages_from_env();
+        let de = DesktopEntry::from_path(path, Some(&locales)).unwrap();
+        let result = de.parse_exec_with_uris(&["src/lib.rs"], &locales);
+
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    #[ignore = "Needs a desktop environment with Nautilus installed, run locally only"]
+    fn should_parse_exec_with_dbus_and_field_codes() {
+        let path = PathBuf::from("/usr/share/applications/org.gnome.Nautilus.desktop");
+        let locales = get_languages_from_env();
+        let de = DesktopEntry::from_path(path, Some(&locales)).unwrap();
+        let _result = de.parse_exec_with_uris(&[], &locales);
+        let path = std::env::current_dir().unwrap();
+        let path = path.to_string_lossy();
+        let path = format!("file:///{path}");
+        let result = de.parse_exec_with_uris(&[path.as_str()], &locales);
+
+        assert!(result.is_ok());
+    }
+}

src/exec.rs

@@ -4,6 +4,9 @@
 mod decoder;
 mod iter;
 
+mod exec;
+pub use exec::ExecError;
+
 pub mod matching;
 pub use decoder::DecodeError;
 
@@ -477,7 +480,7 @@ fn env_with_locale() {
     let locales = &["fr_FR"];
 
     let de = DesktopEntry::from_path(
-        PathBuf::from("tests/org.mozilla.firefox.desktop"),
+        PathBuf::from("tests_entries/org.mozilla.firefox.desktop"),
         Some(locales),
     )
     .unwrap();

src/lib.rs

@@ -0,0 +1,19 @@
+[Desktop Entry]
+Type=Application
+TryExec=alacritty
+Exec=alacritty
+Icon=Alacritty
+Terminal=false
+Categories=System;TerminalEmulator;
+
+Name=Alacritty
+GenericName=Terminal
+Comment=A fast, cross-platform, OpenGL terminal emulator
+StartupWMClass=Alacritty
+Actions=New;
+
+X-Desktop-File-Install-Version=0.26
+
+[Desktop Action New]
+Name=New Terminal
+Exec=alacritty

tests/code.desktop renamed to tests_entries/code.desktop

@@ -0,0 +1,5 @@
+[Desktop Entry]
+Exec=
+Terminal=false
+Type=Application
+Name=NoExecKey

tests/com.brave.Browser.flextop.brave-cinhimbnkkaeohfgghhklpknlkffjgod-Default.desktop renamed to tests_entries/com.brave.Browser.flextop.brave-cinhimbnkkaeohfgghhklpknlkffjgod-Default.desktop

@@ -0,0 +1,5 @@
+[Desktop Entry]
+Exec=alacritty -e glxgears -info
+Terminal=false
+Type=Application
+Name=GlxGearNoTerminal