test: Add tests for primary selection

Author: Muscraft

tests/color/first_snippet_is_primary.rs

@@ -0,0 +1,48 @@
+use annotate_snippets::{AnnotationKind, Group, Level, Renderer, Snippet};
+
+use snapbox::{assert_data_eq, file};
+
+#[test]
+fn case() {
+    let file_txt_source = r#"this is from a txt file"#;
+
+    let rust_source = r#"fn main() {
+    let b: &[u8] = include_str!("file.txt");
+    let s: &str = include_bytes!("file.txt");
+}"#;
+
+    let input = &[
+        Group::with_title(Level::ERROR.title("mismatched types").id("E0308"))
+            .element(
+                Snippet::source(file_txt_source)
+                    .line_start(3)
+                    .path("$DIR/file.txt")
+                    .annotation(
+                        AnnotationKind::Context
+                            .span(0..23)
+                            .label("the macro expands to this string"),
+                    ),
+            )
+            .element(
+                Snippet::source(rust_source)
+                    .path("$DIR/mismatched-types.rs")
+                    .annotation(
+                        AnnotationKind::Context
+                            .span(23..28)
+                            .label("expected due to this"),
+                    )
+                    .annotation(
+                        AnnotationKind::Primary
+                            .span(31..55)
+                            .label("expected `&[u8]`, found `&str`"),
+                    ),
+            )
+            .element(
+                Level::NOTE
+                    .message("expected reference `&[u8]`\n   found reference `&'static str`"),
+            ),
+    ];
+    let expected = file!["first_snippet_is_primary.term.svg"];
+    let renderer = Renderer::styled();
+    assert_data_eq!(renderer.render(input), expected);
+}

tests/color/first_snippet_is_primary.term.svg

@@ -4,6 +4,7 @@ mod ann_multiline;
 mod ann_multiline2;
 mod ann_removed_nl;
 mod ensure_emoji_highlight_width;
+mod first_snippet_is_primary;
 mod fold_ann_multiline;
 mod fold_bad_origin_line;
 mod fold_leading;