highlighter: Fix condition checking for overlapping injection ranges

This fixes a case which could cause injections to become out of order.
The test case has two patterns that emit overlapping captures for an
injection, one at bytes 11..52 and another at 20..51. If the pattern
shown in the test case comes later in the file than the pattern in Rust
injections that highlights macro invocation token tree nodes, then the
larger capture (11..52) comes after the smaller one (20..51). The
part of the injections that decides precedence didn't handle this case
as the larger range ends after the smaller range. We change this
condition to do a generic intersection/overlap check.

Author: the-mikedavis

fixtures/injections/overlapping_injection.rs

@@ -0,0 +1,2 @@
+   some_macro!((), (), "`rust` injection happens here");
+//                     ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┹─ rust

highlighter/src/injections_query.rs

@@ -409,7 +409,7 @@ impl Syntax {
             // that injections get sorted to the correct position
             if let Some(last_injection) = injections
                 .last()
-                .filter(|injection| injection.range.end >= matched_node_range.end)
+                .filter(|injection| ranges_intersect(&injection.range, &matched_node_range))
             {
                 // this condition is not needed but serves as fast path
                 // for common cases
@@ -703,3 +703,8 @@ fn intersect_ranges_impl(
         push_range(start..range.end)
     }
 }
+
+fn ranges_intersect(a: &Range, b: &Range) -> bool {
+    // Adapted from <https://github.com/helix-editor/helix/blob/8df58b2e1779dcf0046fb51ae1893c1eebf01e7c/helix-core/src/selection.rs#L156-L163>
+    a.start == b.start || (a.end > b.start && b.end > a.start)
+}

highlighter/src/tests.rs

@@ -341,6 +341,7 @@ fn injection_precedence() {
  "#,
     );
     highlight_fixture(&loader, "highlighter/rust_doc_comment.rs");
+
     loader.shadow_injections(
         "rust",
         r#"
@@ -355,4 +356,24 @@ fn injection_precedence() {
     );
     highlight_fixture(&loader, "highlighter/rust_no_doc_comment.rs");
     injection_fixture(&loader, "injections/rust_no_doc_comment.rs");
+
+    loader.shadow_injections(
+        "rust",
+        r#"
+((macro_invocation
+   macro:
+     [
+       (scoped_identifier
+         name: (_) @_macro_name)
+       (identifier) @_macro_name
+     ]
+   (token_tree . (_) . (_) . (string_literal) @injection.content))
+ (#any-of? @_macro_name
+  ; std
+  "some_macro")
+  (#set! injection.language "rust")
+  (#set! injection.include-children))
+    "#,
+    );
+    injection_fixture(&loader, "injections/overlapping_injection.rs");
 }