Use separate Git repository for snapshot testing

closes #161

Cargo.lock

@@ -51,6 +51,7 @@ dependencies = [
  "git2 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "syntect 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tempdir 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -505,6 +506,14 @@ dependencies = [
  "ucd-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "remove_dir_all"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "safemem"
 version = "0.2.0"
@@ -598,6 +607,15 @@ dependencies = [
  "yaml-rust 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "tempdir"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "remove_dir_all 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "term_size"
 version = "0.3.1"
@@ -831,6 +849,7 @@ dependencies = [
 "checksum regex 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9329abc99e39129fcceabd24cf5d85b4671ef7c29c50e972bc5afe32438ec384"
 "checksum regex-syntax 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "8e931c58b93d86f080c734bfd2bce7dd0079ae2331235818133c8be7f422e20e"
 "checksum regex-syntax 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)" = "7d707a4fa2637f2dca2ef9fd02225ec7661fe01a53623c1e6515b6916511f7a7"
+"checksum remove_dir_all 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3488ba1b9a2084d38645c4c08276a1752dcbf2c7130d74f1569681ad5d2799c5"
 "checksum safemem 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e27a8b19b835f7aea908818e871f5cc3a5a186550c30773be987e155e8163d8f"
 "checksum same-file 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "cfb6eded0b06a0b512c8ddbcf04089138c9b4362c2f696f3c3d76039d68f3637"
 "checksum serde 1.0.51 (registry+https://github.com/rust-lang/crates.io-index)" = "21924cc18e5281f232a17c040355fac97732b42cf019c24996a1642bcb169cdb"
@@ -842,6 +861,7 @@ dependencies = [
 "checksum strsim 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bb4f380125926a99e52bc279241539c018323fab05ad6368b56f93d9369ff550"
 "checksum syn 0.13.7 (registry+https://github.com/rust-lang/crates.io-index)" = "61b8f1b737f929c6516ba46a3133fd6d5215ad8a62f66760f851f7048aebedfb"
 "checksum syntect 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "dc8a6f0db88d4afc340522c20d260411e746b2225b257c6b238a75de9d7cec78"
+"checksum tempdir 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)" = "15f2b5fb00ccdf689e0149d1b1b3c03fead81c2b37735d812fa8bddbbf41b6d8"
 "checksum term_size 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9e5b9a66db815dcfd2da92db471106457082577c3c278d4138ab3e3b4e189327"
 "checksum termion 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "689a3bdfaab439fd92bc87df5c4c78417d3cbe537487274e9b0b2dce76e92096"
 "checksum termios 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "d5d9cf598a6d7ce700a4e6a9199da127e6819a61e64b68609683cc9a01b5683a"

Cargo.toml

@@ -39,3 +39,6 @@ features = ["suggestions", "color", "wrap_help"]
 version = "0.11"
 default-features = false
 features = []
+
+[dev-dependencies]
+tempdir = "0.3"

tests/tester.rs

@@ -1,16 +1,29 @@
 use std::env;
 use std::fs::{self, File};
-use std::io::Read;
-use std::path::PathBuf;
+use std::io::{self, Read};
+use std::path::{Path, PathBuf};
 use std::process::Command;
 
+extern crate tempdir;
+use self::tempdir::TempDir;
+
+extern crate git2;
+use self::git2::build::CheckoutBuilder;
+use self::git2::Error;
+use self::git2::Repository;
+use self::git2::Signature;
+
 pub struct BatTester {
+    /// Temporary working directory
+    temp_dir: TempDir,
+
+    /// Path to the *bat* executable
     exe: PathBuf,
 }
 
 impl BatTester {
     pub fn new() -> Self {
-        modify_sample_file();
+        let temp_dir = create_sample_directory().expect("sample directory");
 
         let root = env::current_exe()
             .expect("tests executable")
@@ -21,17 +34,18 @@ impl BatTester {
             .to_path_buf();
 
         let exe_name = if cfg!(windows) { "bat.exe" } else { "bat" };
+        let exe = root.join(exe_name);
 
-        BatTester {
-            exe: root.join(exe_name),
-        }
+        BatTester { temp_dir, exe }
     }
 
     pub fn test_snapshot(&self, style: &str) {
         let output = Command::new(&self.exe)
-            .args(&["tests/snapshots/sample.rs", &format!("--style={}", style)])
+            .current_dir(self.temp_dir.path())
+            .args(&["sample.rs", &format!("--style={}", style)])
             .output()
             .expect("bat failed");
+
         // have to do the replace because the filename in the header changes based on the current working directory
         let actual = String::from_utf8_lossy(&output.stdout)
             .as_ref()
@@ -47,26 +61,35 @@ impl BatTester {
     }
 }
 
-impl Drop for BatTester {
-    fn drop(&mut self) {
-        undo_sample_file_modification();
-    }
-}
+fn create_sample_directory() -> Result<TempDir, git2::Error> {
+    // Create temp directory and initialize repository
+    let temp_dir = TempDir::new("bat-tests").expect("Temp directory");
+    let repo = Repository::init(&temp_dir)?;
 
-fn modify_sample_file() {
-    fs::copy(
-        "tests/snapshots/sample.modified.rs",
-        "tests/snapshots/sample.rs",
-    ).expect("generating modified sample file failed");
-}
+    // Copy over `sample.rs`
+    let sample_path = temp_dir.path().join("sample.rs");
+    println!("{:?}", &sample_path);
+    fs::copy("tests/snapshots/sample.rs", &sample_path).expect("successful copy");
 
-fn undo_sample_file_modification() {
-    let output = Command::new("git")
-        .args(&["checkout", "--", "tests/snapshots/sample.rs"])
-        .output()
-        .expect("git checkout failed");
+    // Commit
+    let mut index = repo.index()?;
+    index.add_path(Path::new("sample.rs"))?;
 
-    if !output.status.success() {
-        panic!("undoing modified sample changes failed")
-    }
+    let oid = index.write_tree()?;
+    let signature = Signature::now("bat test runner", "bat@test.runner")?;
+    let tree = repo.find_tree(oid)?;
+    repo.commit(
+        Some("HEAD"), //  point HEAD to our new commit
+        &signature,   // author
+        &signature,   // committer
+        "initial commit",
+        &tree,
+        &[],
+    );
+    let mut opts = CheckoutBuilder::new();
+    repo.checkout_head(Some(opts.force()))?;
+
+    fs::copy("tests/snapshots/sample.modified.rs", &sample_path).expect("successful copy");
+
+    Ok(temp_dir)
 }