Adds example and a testable docstring for assert_diff

.travis.yml

@@ -10,16 +10,17 @@ install:
   # Install rustfmt
   # There are no linux binaries for rustfmt-bin available right now. See https://github.com/japaric/rustfmt-bin/issues/2.
   #- curl -LSfs https://japaric.github.io/trust/install.sh | sh -s -- --force --crate rustfmt --git japaric/rustfmt-bin --tag v0.9.0-20170614
-  - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (cargo install rustfmt --vers 0.9.0 --force) fi
+  - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (rustup component add rustfmt) fi
   # Install clippy
-  - if [ "$TRAVIS_RUST_VERSION" = "nightly" ]; then (cargo install clippy --force) fi
+  - if [ "$TRAVIS_RUST_VERSION" = "nightly" ]; then (rustup component add rustfmt --toolchain nightly) fi
   - export PATH=$HOME/.cargo/bin:$PATH
 
 script:
   - cargo build --features=bin
   - cargo test
-  - if [ "$TRAVIS_RUST_VERSION" = "nightly" ]; then (cargo clippy) fi
-  - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (cargo fmt -- --write-mode=diff) fi
+  - if [ "$TRAVIS_RUST_VERSION" = "nightly" ]; then (cargo +nightly fmt) fi
+  # Rustfmt.toml rules aren't supported by stable cargo fmt
+  # - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (cargo fmt --all -- --check) fi
 
 addons:
   apt:

examples/assert_diff.rs

@@ -0,0 +1,25 @@
+extern crate term;
+
+#[macro_use(assert_diff)]
+extern crate difference;
+
+
+fn compare_multiline() {
+    let multi_line = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.\nUt enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.\nDuis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.\nExcepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.";
+    let multi_line_missing_full_stop = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.\nUt enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.\nDuis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.\nExcepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum";
+    assert_diff!(multi_line, multi_line, "\n", 0);
+    assert_diff!(multi_line, multi_line_missing_full_stop, "\n", 2);
+}
+
+fn compare_single_line() {
+    let lorem_ipsum = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.";
+    let lorem_ipsum2 = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.";
+    let lorem_ipsum_missing_full_stop = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua";
+    assert_diff!(lorem_ipsum, lorem_ipsum2, " ", 0);
+    assert_diff!(lorem_ipsum, lorem_ipsum_missing_full_stop, " ", 2);
+}
+
+fn main() {
+    compare_multiline();
+    compare_single_line();
+}

src/lib.rs

@@ -38,9 +38,9 @@
 #![deny(missing_docs)]
 #![deny(warnings)]
 
+mod display;
 mod lcs;
 mod merge;
-mod display;
 
 use lcs::lcs;
 use merge::merge;
@@ -140,14 +140,21 @@ pub fn diff(orig: &str, edit: &str, split: &str) -> (i32, Vec<Difference>) {
 
 /// Assert the difference between two strings. Works like diff, but takes
 /// a fourth parameter that is the expected edit distance (e.g. 0 if you want to
+/// takes 4 arguments: (first_string, second_string, split_char, expected_distance)
 /// test for equality).
 ///
 /// To include this macro use:
 ///
 /// ```
 /// #[macro_use(assert_diff)]
 /// extern crate difference;
-/// # fn main() { }
+/// # fn main() {
+///    let lorem_ipsum = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.";
+///    let lorem_ipsum2 = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.";
+///    let lorem_ipsum_missing_full_stop = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua";
+///    assert_diff!(lorem_ipsum, lorem_ipsum2, " ", 0);
+///    assert_diff!(lorem_ipsum, lorem_ipsum_missing_full_stop, " ", 2);
+/// }
 /// ```
 ///
 /// Remember that edit distance might not be equal to your understanding of difference,
@@ -157,21 +164,23 @@ pub fn diff(orig: &str, edit: &str, split: &str) -> (i32, Vec<Difference>) {
 /// Will print an error with a colorful diff in case of failure.
 #[macro_export]
 macro_rules! assert_diff {
-    ($orig:expr , $edit:expr, $split: expr, $expected: expr) => ({
+    ($orig:expr , $edit:expr, $split: expr, $expected: expr) => {{
         let orig = $orig;
         let edit = $edit;
 
         let changeset = $crate::Changeset::new(orig, edit, &($split));
         if changeset.distance != $expected {
             println!("{}", changeset);
-            panic!("assertion failed: edit distance between {:?} and {:?} is {} and not {}, see \
-                    diffset above",
-                   orig,
-                   edit,
-                   changeset.distance,
-                   &($expected))
+            panic!(
+                "assertion failed: edit distance between {:?} and {:?} is {} and not {}, see \
+                 diffset above",
+                orig,
+                edit,
+                changeset.distance,
+                &($expected)
+            )
         }
-    })
+    }};
 }
 
 /// **This function is deprecated, `Changeset` now implements the `Display` trait instead**