feat(config): embed the default configuration file into the binary

git-cliff-core/Cargo.toml

@@ -17,6 +17,7 @@ tera = "1.12.1"
 regex = "1.5.4"
 serde_regex = "1.1.0"
 indexmap = "1.7.0"
+toml = "0.5.8"
 
 [dependencies.git2]
 version = "0.13.21"
@@ -27,9 +28,13 @@ version = "0.11.0"
 default-features = false
 features = ["toml", "yaml"]
 
-[dev-dependencies]
-pretty_assertions = "0.7"
-
 [dependencies.git-conventional]
 version = "0.9.2"
 features = ["serde"]
+
+[dependencies.rust-embed]
+version = "6.0.0"
+features = ["debug-embed"]
+
+[dev-dependencies]
+pretty_assertions = "0.7"

git-cliff-core/src/embed.rs

@@ -0,0 +1,37 @@
+#![allow(missing_docs)] // RustEmbed generated functions does not have doc comments
+
+use crate::config::Config;
+use crate::error::{
+	Error,
+	Result,
+};
+use rust_embed::RustEmbed;
+use std::str;
+
+/// Configuration file embedder/extractor.
+///
+/// Embeds `config/`[`DEFAULT_CONFIG`] into the binary.
+///
+/// [`DEFAULT_CONFIG`]: crate::DEFAULT_CONFIG
+#[derive(Debug, RustEmbed)]
+#[folder = "../config/"]
+pub struct EmbeddedConfig;
+
+impl EmbeddedConfig {
+	/// Extracts the embedded content.
+	pub fn get_config() -> Result<String> {
+		match Self::get(crate::DEFAULT_CONFIG) {
+			Some(v) => Ok(str::from_utf8(&v.data.into_owned()).unwrap().to_string()),
+			None => Err(Error::EmbeddedError(String::from(
+				"Embedded config not found",
+			))),
+		}
+	}
+
+	/// Parses the extracted content into [`Config`].
+	///
+	/// [`Config`]: Config
+	pub fn parse() -> Result<Config> {
+		Ok(toml::from_str(&Self::get_config()?)?)
+	}
+}

git-cliff-core/src/error.rs

@@ -28,6 +28,12 @@ pub enum Error {
 	/// Error that may occur while parsing the command line arguments.
 	#[error("Argument error: `{0}`")]
 	ArgumentError(String),
+	/// Error that may occur while extracting the embedded content.
+	#[error("Embedded error: `{0}`")]
+	EmbeddedError(String),
+	/// Errors that may occur when deserializing types from TOML format.
+	#[error("Cannot parse TOML: `{0}`")]
+	DeserializeError(#[from] toml::de::Error),
 }
 
 /// Result type of the core library.

git-cliff-core/src/lib.rs

@@ -7,6 +7,8 @@ pub use regex;
 pub mod commit;
 /// Config file parser.
 pub mod config;
+/// Embedded file handler.
+pub mod embed;
 /// Error handling.
 pub mod error;
 /// Common release type.

git-cliff/src/lib.rs

@@ -10,6 +10,7 @@ use args::Opt;
 use changelog::Changelog;
 use git_cliff_core::commit::Commit;
 use git_cliff_core::config::Config;
+use git_cliff_core::embed::EmbeddedConfig;
 use git_cliff_core::error::{
 	Error,
 	Result,
@@ -38,13 +39,19 @@ pub fn run(mut args: Opt) -> Result<()> {
 	}
 
 	// Parse configuration file.
-	let mut config = Config::parse(match args.config.to_str() {
+	let path = match args.config.to_str() {
 		Some(v) => Ok(v.to_string()),
 		None => Err(Error::IoError(io::Error::new(
 			io::ErrorKind::Other,
 			"path contains invalid characters",
 		))),
-	}?)?;
+	}?;
+	let mut config = if fs::metadata(&path).is_ok() {
+		Config::parse(path)?
+	} else {
+		warn!("{:?} is not found, using the default configuration.", path);
+		EmbeddedConfig::parse()?
+	};
 
 	// Update the configuration based on command line arguments.
 	match args.strip.as_deref() {