Support cargo new/init --force

Author: dwijnand

src/cargo/ops/cargo_new.rs

@@ -32,6 +32,7 @@ pub struct NewOptions {
     pub path: PathBuf,
     pub name: Option<String>,
     pub edition: Option<String>,
+    pub force: bool,
     pub registry: Option<String>,
 }
 
@@ -81,6 +82,7 @@ impl NewOptions {
         path: PathBuf,
         name: Option<String>,
         edition: Option<String>,
+        force: bool,
         registry: Option<String>,
     ) -> CargoResult<NewOptions> {
         let kind = match (bin, lib) {
@@ -96,6 +98,7 @@ impl NewOptions {
             path,
             name,
             edition,
+            force,
             registry,
         };
         Ok(opts)
@@ -301,7 +304,7 @@ fn plan_new_source_file(bin: bool, package_name: String) -> SourceFileInformatio
 
 pub fn new<'a>(opts: &'a NewOptions, config: &Config) -> CargoResult<&'a str> {
     let path = &opts.path;
-    if fs::metadata(path).is_ok() {
+    if fs::metadata(path).is_ok() && !opts.force {
         failure::bail!(
             "destination `{}` already exists\n\n\
              Use `cargo init` to initialize the directory",
@@ -335,7 +338,7 @@ pub fn new<'a>(opts: &'a NewOptions, config: &Config) -> CargoResult<&'a str> {
 pub fn init(opts: &NewOptions, config: &Config) -> CargoResult<()> {
     let path = &opts.path;
 
-    if fs::metadata(&path.join("Cargo.toml")).is_ok() {
+    if fs::metadata(&path.join("Cargo.toml")).is_ok() && !opts.force {
         failure::bail!("`cargo init` cannot be run on existing Cargo packages")
     }
 

src/cargo/util/command_prelude.rs

@@ -171,6 +171,7 @@ pub trait AppExt: Sized {
             )
             .value_name("NAME"),
         )
+        ._arg(opt("force", "Force initialising over existing files").short("f"))
         ._arg(opt("registry", "Registry to use").value_name("REGISTRY"))
     }
 
@@ -381,6 +382,7 @@ pub trait ArgMatchesExt {
             self.value_of_path("path", config).unwrap(),
             self._value_of("name").map(|s| s.to_string()),
             self._value_of("edition").map(|s| s.to_string()),
+            self._is_present("force"),
             self.registry(config)?,
         )
     }

tests/testsuite/init.rs

@@ -276,6 +276,16 @@ fn auto_git() {
     assert!(paths::root().join(".gitignore").is_file());
 }
 
+#[test]
+fn force() {
+    cargo_process("init").run();
+    cargo_process("init")
+        .with_status(101)
+        .with_stderr("[ERROR] `cargo init` cannot be run on existing Cargo packages")
+        .run();
+    cargo_process("init --force").run();
+}
+
 #[test]
 fn invalid_dir_name() {
     let foo = &paths::root().join("foo.bar");

tests/testsuite/new.rs

@@ -120,6 +120,12 @@ fn existing() {
         .run();
 }
 
+#[test]
+fn force() {
+    fs::create_dir(paths::root().join("foo")).unwrap();
+    cargo_process("new --force foo").run();
+}
+
 #[test]
 fn invalid_characters() {
     cargo_process("new foo.rs")