Allow git subfolder as a template.

Using cargo generate --git <repo>#<sub-folder, this one
1) Allows to use a subfolder as the actual template (see #47)
2) Allows to e.g. generate a project from an example in a repo (see #78)
3) Avoids the conflicting requirements for cargo-generate#295 and cargo-generate#291, allowing for easier implementation of `--pick` for cargo-generate#291.

README.md

@@ -62,6 +62,16 @@ You can also pass the name of your project to the tool using the `--name` or `-n
 cargo generate --git https://github.com/githubusername/mytemplate.git --name myproject
 ```
 
+If the git repository contains multiple templates, the specific subfolder in the git repository may be specified like this:
+
+```sh
+cargo generate --git "https://github.com/githubusername/mytemplate.git <relative-template-path>"
+```
+
+> NOTE: The specified `relative-template-path` will be used as the actual template root, whether or not this is actually true!
+
+> NOTE: When using the `subfolder` feature, `cargo-generate` will search for
+
 ## git over ssh
 
 New in version [0.7.0] is the support for both public and private and ssh git remote urls.
@@ -82,7 +92,7 @@ cargo generate --git rustwasm/wasm-pack-template --name mywasm
 
 ## http(s) proxy
 
-New in version [0.7.0] is automatic proxy usage. So, if http(s)_PROXY env variables are provided, they 
+New in version [0.7.0] is automatic proxy usage. So, if http(s)\_PROXY env variables are provided, they 
 will be used for cloning a http(s) template repository. 
 
 ## Favorites
@@ -94,12 +104,13 @@ Each favorite template is specified in its own section, e.g.:
 
 ```toml
 [favorites.demo]
-description = "Demo template for cargo-generate"
+description = "<optional description, visible with --list-favorites>"
 git = "https://github.com/ashleygwilliams/wasm-pack-template"
-branch = "master"
+branch = "<optional-branch>"
+subfolder = "<optional-subfolder>"
 ```
 
-Both `branch` and `description` are optional, and the branch may be overridden by specifying `--branch <branch>` on the command line.
+Values may be overridden using the CLI arguments of the same names (e.g. `--subfolder` for the `subfolder` value).
 
 When favorites are available, they can be generated simply by invoking:
 
@@ -110,7 +121,7 @@ cargo gen <favorite>
 or slightly more involved:
 
 ```cli
-cargo generate demo --branch master --name expanded_demo
+cargo generate demo --branch mybranch --name expanded_demo --subfolder myfolder
 ```
 
 > NOTE: when `<favorite>` is not defined in the config file, it is interpreted as a git repo like as if `--git <favorite>`
@@ -295,6 +306,8 @@ include = ["Cargo.toml"]
 exclude = ["*.c"]
 ```
 
+The `cargo-generate.toml` file should be placed in the root of the template. If using the `subfolder` feature, the root is the `subfolder` inside the repository, though `cargo-generate` will look for the file in all parent folders until it reaches the repository root.
+
 ## Cargo gen - alias
 
 `cargo gen` requires an [cargo alias](https://doc.rust-lang.org/cargo/reference/config.html) 
@@ -323,4 +336,4 @@ conditions.
 If you want to contribute to `cargo-generate`, please read our [CONTRIBUTING notes].
 
 [CONTRIBUTING notes]: CONTRIBUTING.md
-[0.7.0]: https://github.com/cargo-generate/cargo-generate/releases/tag/v0.7.0
+[0.7.0]: https://github.com/cargo-generate/cargo-generate/releases/tag/v0.7.0

src/app_config.rs

@@ -18,6 +18,7 @@ pub(crate) struct FavoriteConfig {
  pub description: Option<String>,
  pub git: Option<String>,
  pub branch: Option<String>,
+ pub subfolder: Option<String>,
 }
 
 impl Default for AppConfig {

src/config.rs

@@ -51,15 +51,21 @@ impl TryFrom<String> for Config {
 }
 
 impl Config {
- pub(crate) fn new<P: AsRef<Path>>(path: P) -> Result<Option<Self>> {
- match fs::read_to_string(path) {
- Ok(contents) => Config::try_from(contents)
- .map(Option::from)
- .map_err(|e| e.into()),
- Err(e) => match e.kind() {
- ErrorKind::NotFound => Ok(None),
- _ => anyhow::bail!(e),
+ pub(crate) fn from_path<P>(path: &Option<P>) -> Result<Option<Self>>
+ where
+ P: AsRef<Path>,
+ {
+ match path {
+ Some(path) => match fs::read_to_string(path) {
+ Ok(contents) => Config::try_from(contents)
+ .map(Option::from)
+ .map_err(|e| e.into()),
+ Err(e) => match e.kind() {
+ ErrorKind::NotFound => Ok(None),
+ _ => anyhow::bail!(e),
+ },
  },
+ None => Ok(None),
  }
  }
 }
@@ -89,7 +95,7 @@ mod tests {
  )
  .unwrap();
 
- let config = Config::new(&config_path).unwrap().unwrap();
+ let config = Config::from_path(&Some(config_path)).unwrap().unwrap();
 
  assert_eq!(
  config.template,

src/favorites.rs

@@ -37,6 +37,7 @@ pub(crate) fn list_favorites(args: &Args) -> Result<()> {
 
 pub(crate) fn resolve_favorite_args(args: &mut Args) -> Result<()> {
  if args.git.is_some() {
+ args.subfolder = args.favorite.take();
  return Ok(());
  }
 
@@ -48,7 +49,7 @@ pub(crate) fn resolve_favorite_args(args: &mut Args) -> Result<()> {
  let app_config_path = app_config_path(&args.config)?;
  let app_config = AppConfig::from_path(app_config_path.as_path())?;
 
- let (git, branch) = app_config
+ let (git, branch, subfolder) = app_config
  .favorites
  .get(favorite_name.as_str())
  .map_or_else(
@@ -57,17 +58,27 @@ pub(crate) fn resolve_favorite_args(args: &mut Args) -> Result<()> {
  "Favorite {} not found in config, using it as a git repo url",
  style(&favorite_name).bold()
  );
- (Some(favorite_name.clone()), args.branch.as_ref().cloned())
+ (
+ Some(favorite_name.clone()),
+ args.branch.as_ref().cloned(),
+ args.subfolder.clone(),
+ )
  },
  |f| {
  (
  f.git.clone(),
  args.branch.as_ref().or_else(|| f.branch.as_ref()).cloned(),
+ args.subfolder
+ .as_ref()
+ .or_else(|| f.subfolder.as_ref())
+ .cloned(),
  )
  },
  );
+
  args.git = git;
  args.branch = branch;
+ args.subfolder = subfolder;
 
  Ok(())
 }