Add option to specify context size

src/lib.rs

@@ -30,7 +30,7 @@
 //!
 //! ```
 //! use imara_diff::intern::InternedInput;
-//! use imara_diff::{diff, Algorithm, UnifiedDiffBuilder};
+//! use imara_diff::{diff, Algorithm, UnifiedDiffBuilder, unified_diff};
 //!
 //! let before = r#"fn foo() -> Bar {
 //!     let mut foo = 2;
@@ -49,7 +49,7 @@
 //! "#;
 //!
 //! let input = InternedInput::new(before, after);
-//! let diff = diff(Algorithm::Histogram, &input, UnifiedDiffBuilder::new(&input));
+//! let diff = diff(Algorithm::Histogram, &input, UnifiedDiffBuilder::new(&input, unified_diff::ContextSize::symmetrical(3)));
 //! assert_eq!(
 //!     diff,
 //!     r#"@@ -1,5 +1,8 @@
@@ -150,7 +150,7 @@
 //! ```
 
 #[cfg(feature = "unified_diff")]
-pub use unified_diff::UnifiedDiffBuilder;
+pub use unified_diff::_impl::UnifiedDiffBuilder;
 
 use crate::intern::{InternedInput, Token, TokenSource};
 pub use crate::sink::Sink;
@@ -160,7 +160,7 @@ mod myers;
 pub mod sink;
 pub mod sources;
 #[cfg(feature = "unified_diff")]
-mod unified_diff;
+pub mod unified_diff;
 mod util;
 
 #[cfg(test)]

src/tests.rs

@@ -6,7 +6,7 @@ use expect_test::{expect, expect_file};
 
 use crate::intern::InternedInput;
 use crate::sink::Counter;
-use crate::{diff, Algorithm, UnifiedDiffBuilder};
+use crate::{diff, unified_diff::ContextSize, Algorithm, UnifiedDiffBuilder};
 
 #[test]
 fn replace() {
@@ -28,7 +28,11 @@ fn foo() -> Bar{
     let input = InternedInput::new(before, after);
     for algorithm in Algorithm::ALL {
         println!("{algorithm:?}");
-        let diff = diff(algorithm, &input, UnifiedDiffBuilder::new(&input));
+        let diff = diff(
+            algorithm,
+            &input,
+            UnifiedDiffBuilder::new(&input, ContextSize::default()),
+        );
         expect![[r#"
             @@ -1,5 +1,8 @@
             +const TEST: i32 = 0;
@@ -55,7 +59,11 @@ fn identical_files() {
     for algorithm in Algorithm::ALL {
         println!("{algorithm:?}");
         let input = InternedInput::new(file, file);
-        let diff = diff(algorithm, &input, UnifiedDiffBuilder::new(&input));
+        let diff = diff(
+            algorithm,
+            &input,
+            UnifiedDiffBuilder::new(&input, ContextSize::default()),
+        );
         assert_eq!(diff, "");
     }
 }
@@ -76,7 +84,11 @@ fn simple_insert() {
     let mut input = InternedInput::new(before, after);
     for algorithm in Algorithm::ALL {
         println!("{algorithm:?}");
-        let res = diff(algorithm, &input, UnifiedDiffBuilder::new(&input));
+        let res = diff(
+            algorithm,
+            &input,
+            UnifiedDiffBuilder::new(&input, ContextSize::default()),
+        );
         expect![[r#"
           @@ -1,4 +1,5 @@
            fn foo() -> Bar{
@@ -89,7 +101,11 @@ fn simple_insert() {
 
         swap(&mut input.before, &mut input.after);
 
-        let res = diff(algorithm, &input, UnifiedDiffBuilder::new(&input));
+        let res = diff(
+            algorithm,
+            &input,
+            UnifiedDiffBuilder::new(&input, ContextSize::default()),
+        );
         expect![[r#"
             @@ -1,5 +1,4 @@
              fn foo() -> Bar{
@@ -129,8 +145,20 @@ fn hand_checked_udiffs() {
         let before = read_to_string(path_before).unwrap();
         let after = read_to_string(path_after).unwrap();
         let input = InternedInput::new(&*before, &*after);
-        let diff = diff(algorithm, &input, UnifiedDiffBuilder::new(&input));
-        expect_file![path_diff].assert_eq(&diff);
+        let diff_res = diff(
+            algorithm,
+            &input,
+            UnifiedDiffBuilder::new(&input, ContextSize::default()),
+        );
+        expect_file![path_diff].assert_eq(&diff_res);
+        // test with a context of 5 lines
+        let path_diff = test_dir.join(format!("{file}.{algorithm:?}_ctx5.diff"));
+        let diff_res = diff(
+            algorithm,
+            &input,
+            UnifiedDiffBuilder::new(&input, ContextSize::symmetrical(5)),
+        );
+        expect_file![path_diff].assert_eq(&diff_res);
     }
 }