3 files changed, 49 insertions, 19 deletions

diff --git a/libeditor/Cargo.toml b/libeditor/Cargo.toml
index 92abd3289..750d80038 100644
--- a/libeditor/Cargo.toml
+++ b/libeditor/Cargo.toml
@@ -6,3 +6,4 @@ publish = false
 
 [dependencies]
 libsyntax2 = { path = "../" }
+itertools = "0.7.8"
diff --git a/libeditor/src/lib.rs b/libeditor/src/lib.rs
index a0c003fb5..ef31efe35 100644
--- a/libeditor/src/lib.rs
+++ b/libeditor/src/lib.rs
@@ -13,6 +13,7 @@ pub struct File {
     inner: libsyntax2::File
 }
 
+#[derive(Debug)]
 pub struct HighlightedRange {
     pub range: TextRange,
     pub tag: &'static str,
@@ -102,22 +103,3 @@ impl<'f> Declaration<'f> {
         self.0.range()
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_extend_selection() {
-        let text = r#"fn foo() {
-    1 + 1
-}
-"#;
-        let file = File::new(text);
-        let range = TextRange::offset_len(18.into(), 0.into());
-        let range = file.extend_selection(range).unwrap();
-        assert_eq!(range, TextRange::from_to(17.into(), 18.into()));
-        let range = file.extend_selection(range).unwrap();
-        assert_eq!(range, TextRange::from_to(15.into(), 20.into()));
-    }
-}
diff --git a/libeditor/tests/test.rs b/libeditor/tests/test.rs
new file mode 100644
index 000000000..e1c8aee4b
--- /dev/null
+++ b/libeditor/tests/test.rs
@@ -0,0 +1,47 @@
+extern crate libeditor;
+extern crate itertools;
+
+use std::fmt;
+use itertools::Itertools;
+use libeditor::{File, TextRange};
+
+#[test]
+fn test_extend_selection() {
+    let file = file(r#"fn foo() {
+    1 + 1
+}
+"#);
+    let range = TextRange::offset_len(18.into(), 0.into());
+    let range = file.extend_selection(range).unwrap();
+    assert_eq!(range, TextRange::from_to(17.into(), 18.into()));
+    let range = file.extend_selection(range).unwrap();
+    assert_eq!(range, TextRange::from_to(15.into(), 20.into()));
+}
+
+#[test]
+fn test_highlighting() {
+    let file = file(r#"
+// comment
+fn main() {}
+    println!("Hello, {}!", 92);
+"#);
+    let hls = file.highlight();
+    dbg_eq(
+        &hls,
+        r#"[HighlightedRange { range: [1; 11), tag: "comment" },
+            HighlightedRange { range: [12; 14), tag: "keyword" },
+            HighlightedRange { range: [15; 19), tag: "function" },
+            HighlightedRange { range: [29; 36), tag: "text" },
+            HighlightedRange { range: [38; 50), tag: "string" },
+            HighlightedRange { range: [52; 54), tag: "literal" }]"#
+    );
+}
+
+fn file(text: &str) -> File {
+    File::new(text)
+}
+
+fn dbg_eq(actual: &impl fmt::Debug, expected: &str) {
+    let expected = expected.lines().map(|l| l.trim()).join(" ");
+    assert_eq!(actual, expected);
+}