implement git-init

Cargo.toml

@@ -1,12 +1,17 @@
 [package]
 name = "grit-cli"
 version = "1.0.0"
-authors = ["Sebastian Thiel <sthiel@thoughtworks.com>"]
+authors = ["Sebastian Thiel <byronimo@gmail.com>"]
 publish = false
 
 [dependencies]
 failure = "0.1.1"
 failure-tools = "4.0.2"
+clap = "2.31.2"
+
+[dependencies.git-core]
+path = "lib/git-core"
+version = "0.1.0"
 
 [[bin]]
 name="grit"
@@ -15,3 +20,5 @@ path="src/main.rs"
 [profile.release]
 panic = 'unwind'
 incremental = false
+
+[workspace]

README.md

@@ -13,7 +13,7 @@ The CLI uses various libraries to implement
 
 * **git-core**
   * **Repository**
-    * [ ] initialize
+    * [x] initialize
     * [ ] references
     * [ ] index
     * [ ] odb

lib/git-core/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "git-core"
+version = "0.1.0"
+authors = ["Sebastian Thiel <byronimo@gmail.com>"]
+publish = false
+
+[dependencies]
+failure = "0.1.1"

lib/git-core/src/lib.rs

@@ -0,0 +1,138 @@
+#[macro_use]
+extern crate failure;
+
+use failure::{Error, ResultExt};
+use std::{fs::{create_dir, OpenOptions}, io::Write, path::Path, path::PathBuf};
+
+const GIT_DIR_NAME: &'static str = ".git";
+
+const TPL_INFO_EXCLUDE: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/info/exclude");
+const TPL_HOOKS_APPLYPATCH_MSG: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/hooks/applypatch-msg.sample");
+const TPL_HOOKS_COMMIT_MSG: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/hooks/commit-msg.sample");
+const TPL_HOOKS_FSMONITOR_WATCHMAN: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/hooks/fsmonitor-watchman.sample");
+const TPL_HOOKS_POST_UPDATE: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/hooks/post-update.sample");
+const TPL_HOOKS_PRE_APPLYPATCH: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/hooks/pre-applypatch.sample");
+const TPL_HOOKS_PRE_COMMIT: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/hooks/pre-commit.sample");
+const TPL_HOOKS_PRE_PUSH: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/hooks/pre-push.sample");
+const TPL_HOOKS_PRE_REBASE: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/hooks/pre-rebase.sample");
+const TPL_HOOKS_PRE_RECEIVE: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/hooks/pre-receive.sample");
+const TPL_HOOKS_PREPARE_COMMIT_MSG: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/hooks/prepare-commit-msg.sample");
+const TPL_HOOKS_UPDATE: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/hooks/update.sample");
+const TPL_CONFIG: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/config");
+const TPL_DESCRIPTION: &'static [u8] =
+    include_bytes!("../../../tests/snapshots/cli/baseline-init/description");
+const TPL_HEAD: &'static [u8] = include_bytes!("../../../tests/snapshots/cli/baseline-init/HEAD");
+
+struct PathCursor<'a>(&'a mut PathBuf);
+struct NewDir<'a>(&'a mut PathBuf);
+
+impl<'a> PathCursor<'a> {
+    fn at(&mut self, component: &str) -> &Path {
+        self.0.push(component);
+        self.0.as_path()
+    }
+}
+
+impl<'a> NewDir<'a> {
+    fn at(self, component: &str) -> Result<Self, Error> {
+        self.0.push(component);
+        create_dir(&self.0)?;
+        Ok(self)
+    }
+    fn as_mut(&mut self) -> &mut PathBuf {
+        self.0
+    }
+}
+
+impl<'a> Drop for NewDir<'a> {
+    fn drop(&mut self) {
+        self.0.pop();
+    }
+}
+
+impl<'a> Drop for PathCursor<'a> {
+    fn drop(&mut self) {
+        self.0.pop();
+    }
+}
+
+fn write_file(data: &[u8], path: &Path) -> Result<(), Error> {
+    let mut file = OpenOptions::new()
+        .write(true)
+        .create(true)
+        .append(false)
+        .open(path)?;
+    file.write_all(data)
+        .with_context(|_| format!("Could not initialize file at '{}'", path.display()))
+        .map_err(Into::into)
+}
+
+pub fn init() -> Result<(), Error> {
+    let mut cursor = PathBuf::from(GIT_DIR_NAME);
+    if cursor.is_dir() {
+        bail!(
+            "Refusing to initialize the existing '{}' directory",
+            cursor.display()
+        )
+    }
+    create_dir(&cursor)?;
+
+    {
+        let mut cursor = NewDir(&mut cursor).at("info")?;
+        write_file(TPL_INFO_EXCLUDE, PathCursor(cursor.as_mut()).at("exclude"))?;
+    }
+
+    {
+        let mut cursor = NewDir(&mut cursor).at("hooks")?;
+        for (tpl, filename) in &[
+            (TPL_HOOKS_UPDATE, "update.sample"),
+            (TPL_HOOKS_PREPARE_COMMIT_MSG, "prepare-commit-msg.sample"),
+            (TPL_HOOKS_PRE_RECEIVE, "pre-receive.sample"),
+            (TPL_HOOKS_PRE_REBASE, "pre-rebase.sample"),
+            (TPL_HOOKS_PRE_PUSH, "pre-push.sample"),
+            (TPL_HOOKS_PRE_COMMIT, "pre-commit.sample"),
+            (TPL_HOOKS_PRE_APPLYPATCH, "pre-applypatch.sample"),
+            (TPL_HOOKS_POST_UPDATE, "post-update.sample"),
+            (TPL_HOOKS_FSMONITOR_WATCHMAN, "fsmonitor-watchman.sample"),
+            (TPL_HOOKS_COMMIT_MSG, "commit-msg.sample"),
+            (TPL_HOOKS_APPLYPATCH_MSG, "applypatch-msg.sample"),
+        ] {
+            write_file(tpl, PathCursor(cursor.as_mut()).at(filename))?;
+        }
+    }
+
+    {
+        let mut cursor = NewDir(&mut cursor).at("objects")?;
+        create_dir(PathCursor(cursor.as_mut()).at("info"))?;
+        create_dir(PathCursor(cursor.as_mut()).at("pack"))?;
+    }
+
+    {
+        let mut cursor = NewDir(&mut cursor).at("refs")?;
+        create_dir(PathCursor(cursor.as_mut()).at("heads"))?;
+        create_dir(PathCursor(cursor.as_mut()).at("tags"))?;
+    }
+
+    for (tpl, filename) in &[
+        (TPL_HEAD, "HEAD"),
+        (TPL_DESCRIPTION, "description"),
+        (TPL_CONFIG, "config"),
+    ] {
+        write_file(tpl, PathCursor(&mut cursor).at(filename))?;
+    }
+
+    Ok(())
+}

src/main.rs

@@ -1,4 +1,34 @@
 extern crate failure;
 extern crate failure_tools;
+#[macro_use]
+extern crate clap;
+extern crate git_core as git;
 
-fn main() {}
+use failure_tools::ok_or_exit;
+use failure::{Error, ResultExt};
+
+mod app {
+    use clap::{App, AppSettings, SubCommand};
+
+    pub fn new<'a, 'b>() -> App<'a, 'b> {
+        let app: App = app_from_crate!();
+        app.setting(AppSettings::SubcommandRequired).subcommand(
+            SubCommand::with_name("init")
+                .alias("initialize")
+                .about("Initialize the repository in the current directory."),
+        )
+    }
+}
+
+fn run() -> Result<(), Error> {
+    let app = app::new();
+    let matches = app.get_matches();
+    match matches.subcommand() {
+        ("init", Some(_args)) => git::init().with_context(|_| "Repository initialization failed"),
+        _ => unreachable!(),
+    }.map_err(Into::into)
+}
+
+fn main() {
+    ok_or_exit(run())
+}

tests/snapshots/cli/init-fail

@@ -0,0 +1,3 @@
+error: Repository initialization failed
+Caused by: 
+ 1: Refusing to initialize the existing '.git' directory

tests/stateless-journey.sh

@@ -9,28 +9,37 @@ exe="${root}/../$exe"
 # shellcheck disable=1090
 source "$root/utilities.sh"
 snapshot="$root/snapshots/cli"
-fixture="$root/fixtures"
+# fixture="$root/fixtures"
 
 SUCCESSFULLY=0
 WITH_FAILURE=1
 
 title "CLI"
 (when "initializing a repository"
-  (sandbox
-    precondition "an initialized baseline repository" && {
-      git init &>/dev/null
-      expect_snapshot "$snapshot/baseline-init" .git
-    }
-  )
-  (sandbox
-    it "succeeds" && {
-      WITH_SNAPSHOT="$snapshot/init-success" \
-      expect_run $SUCCESSFULLY "$exe" init
-    }
+  (with "an empty directory"
+    (sandbox
+      precondition "an initialized baseline repository" && {
+        git init &>/dev/null
+        expect_snapshot "$snapshot/baseline-init" .git
+      }
+    )
+    (sandbox
+      it "succeeds" && {
+        WITH_SNAPSHOT="$snapshot/init-success" \
+        expect_run $SUCCESSFULLY "$exe" init
+      }
 
-    it "matches the output of baseline git init" && {
-      expect_snapshot "$snapshot/baseline-init" .git
-    }
+      it "matches the output of baseline git init" && {
+        expect_snapshot "$snapshot/baseline-init" .git
+      }
+
+      (when "trying to initialize the same directory again"
+        it "fails" && {
+          WITH_SNAPSHOT="$snapshot/init-fail" \
+          expect_run $WITH_FAILURE "$exe" init
+        }
+      )
+    )
   )
 )