From 54975a06d41eb142077aaf2732bfe563a26efa31 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Thu, 21 Mar 2024 11:51:15 -0500
Subject: [PATCH 1/4] test: Clarify test case name

---
 tests/fixtures/no-color/{one_past.svg => ann_removed_nl.svg}   | 0
 tests/fixtures/no-color/{one_past.toml => ann_removed_nl.toml} | 0
 2 files changed, 0 insertions(+), 0 deletions(-)
 rename tests/fixtures/no-color/{one_past.svg => ann_removed_nl.svg} (100%)
 rename tests/fixtures/no-color/{one_past.toml => ann_removed_nl.toml} (100%)

diff --git a/tests/fixtures/no-color/one_past.svg b/tests/fixtures/no-color/ann_removed_nl.svg
similarity index 100%
rename from tests/fixtures/no-color/one_past.svg
rename to tests/fixtures/no-color/ann_removed_nl.svg
diff --git a/tests/fixtures/no-color/one_past.toml b/tests/fixtures/no-color/ann_removed_nl.toml
similarity index 100%
rename from tests/fixtures/no-color/one_past.toml
rename to tests/fixtures/no-color/ann_removed_nl.toml

From 01ca512f66fc38f9fd3ce6f4ad103e97fb91ffd2 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Thu, 21 Mar 2024 11:53:17 -0500
Subject: [PATCH 2/4] test: Show existing EOF annotation behavior

---
 tests/fixtures/no-color/ann_eof.svg  | 33 ++++++++++++++++++++++++++++
 tests/fixtures/no-color/ann_eof.toml | 12 ++++++++++
 2 files changed, 45 insertions(+)
 create mode 100644 tests/fixtures/no-color/ann_eof.svg
 create mode 100644 tests/fixtures/no-color/ann_eof.toml

diff --git a/tests/fixtures/no-color/ann_eof.svg b/tests/fixtures/no-color/ann_eof.svg
new file mode 100644
index 0000000..ba3b204
--- /dev/null
+++ b/tests/fixtures/no-color/ann_eof.svg
@@ -0,0 +1,33 @@
+<svg width="740px" height="128px" xmlns="http://www.w3.org/2000/svg">
+  <style>
+    .fg { fill: #AAAAAA }
+    .bg { background: #000000 }
+    .container {
+      padding: 0 10px;
+      line-height: 18px;
+    }
+    tspan {
+      font: 14px SFMono-Regular, Consolas, Liberation Mono, Menlo, monospace;
+      white-space: pre;
+      line-height: 18px;
+    }
+  </style>
+
+  <rect width="100%" height="100%" y="0" rx="4.5" class="bg" />
+
+  <text xml:space="preserve" class="container fg">
+    <tspan x="10px" y="28px"><tspan>error: expected `.`, `=`</tspan>
+</tspan>
+    <tspan x="10px" y="46px"><tspan> --&gt; Cargo.toml:1:5</tspan>
+</tspan>
+    <tspan x="10px" y="64px"><tspan>  |</tspan>
+</tspan>
+    <tspan x="10px" y="82px"><tspan>1 | asdf</tspan>
+</tspan>
+    <tspan x="10px" y="100px"><tspan>  |     </tspan>
+</tspan>
+    <tspan x="10px" y="118px"><tspan>  |</tspan>
+</tspan>
+  </text>
+
+</svg>
diff --git a/tests/fixtures/no-color/ann_eof.toml b/tests/fixtures/no-color/ann_eof.toml
new file mode 100644
index 0000000..313d220
--- /dev/null
+++ b/tests/fixtures/no-color/ann_eof.toml
@@ -0,0 +1,12 @@
+[message]
+level = "Error"
+title = "expected `.`, `=`"
+
+[[message.snippets]]
+source = "asdf"
+line_start = 1
+origin = "Cargo.toml"
+[[message.snippets.annotations]]
+label = ""
+level = "Error"
+range = [4, 4]

From 0e820651c901ed2772a842d45d033f1c6ff1c5e9 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Thu, 21 Mar 2024 11:54:45 -0500
Subject: [PATCH 3/4] test: Show existing empty span behavior

---
 tests/fixtures/no-color/ann_insertion.svg  | 33 ++++++++++++++++++++++
 tests/fixtures/no-color/ann_insertion.toml | 12 ++++++++
 2 files changed, 45 insertions(+)
 create mode 100644 tests/fixtures/no-color/ann_insertion.svg
 create mode 100644 tests/fixtures/no-color/ann_insertion.toml

diff --git a/tests/fixtures/no-color/ann_insertion.svg b/tests/fixtures/no-color/ann_insertion.svg
new file mode 100644
index 0000000..ba3b204
--- /dev/null
+++ b/tests/fixtures/no-color/ann_insertion.svg
@@ -0,0 +1,33 @@
+<svg width="740px" height="128px" xmlns="http://www.w3.org/2000/svg">
+  <style>
+    .fg { fill: #AAAAAA }
+    .bg { background: #000000 }
+    .container {
+      padding: 0 10px;
+      line-height: 18px;
+    }
+    tspan {
+      font: 14px SFMono-Regular, Consolas, Liberation Mono, Menlo, monospace;
+      white-space: pre;
+      line-height: 18px;
+    }
+  </style>
+
+  <rect width="100%" height="100%" y="0" rx="4.5" class="bg" />
+
+  <text xml:space="preserve" class="container fg">
+    <tspan x="10px" y="28px"><tspan>error: expected `.`, `=`</tspan>
+</tspan>
+    <tspan x="10px" y="46px"><tspan> --&gt; Cargo.toml:1:5</tspan>
+</tspan>
+    <tspan x="10px" y="64px"><tspan>  |</tspan>
+</tspan>
+    <tspan x="10px" y="82px"><tspan>1 | asdf</tspan>
+</tspan>
+    <tspan x="10px" y="100px"><tspan>  |     </tspan>
+</tspan>
+    <tspan x="10px" y="118px"><tspan>  |</tspan>
+</tspan>
+  </text>
+
+</svg>
diff --git a/tests/fixtures/no-color/ann_insertion.toml b/tests/fixtures/no-color/ann_insertion.toml
new file mode 100644
index 0000000..ffd2140
--- /dev/null
+++ b/tests/fixtures/no-color/ann_insertion.toml
@@ -0,0 +1,12 @@
+[message]
+level = "Error"
+title = "expected `.`, `=`"
+
+[[message.snippets]]
+source = "asf"
+line_start = 1
+origin = "Cargo.toml"
+[[message.snippets.annotations]]
+label = "'d' belongs here"
+level = "Error"
+range = [2, 2]

From 7310fd4c45ed2d92f0ecabb155ba8e5a3bb86bb2 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Thu, 21 Mar 2024 11:58:03 -0500
Subject: [PATCH 4/4] fix: Allow empty spans

---
 src/renderer/display_list.rs              | 14 ++++++++------
 tests/fixtures/no-color/ann_eof.svg       |  2 +-
 tests/fixtures/no-color/ann_insertion.svg |  6 +++---
 3 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/src/renderer/display_list.rs b/src/renderer/display_list.rs
index 53caa38..4d2836a 100644
--- a/src/renderer/display_list.rs
+++ b/src/renderer/display_list.rs
@@ -1057,6 +1057,7 @@ fn format_body(
                 Range { start, .. } if start > line_end_index => true,
                 Range { start, end }
                     if start >= line_start_index && end <= line_end_index
+                        // Allow annotating eof or stripped eol
                         || start == line_end_index && end - start <= 1 =>
                 {
                     if let DisplayLine::Source {
@@ -1068,14 +1069,15 @@ fn format_body(
                             .chars()
                             .map(|c| unicode_width::UnicodeWidthChar::width(c).unwrap_or(0))
                             .sum::<usize>();
-                        // This allows for annotations to be placed one past the
-                        // last character
-                        let safe_end = (end - line_start_index).saturating_sub(line_length);
-                        let annotation_end_col = line[0..(end - line_start_index) - safe_end]
+                        let mut annotation_end_col = line
+                            [0..(end - line_start_index).min(line_length)]
                             .chars()
                             .map(|c| unicode_width::UnicodeWidthChar::width(c).unwrap_or(0))
-                            .sum::<usize>()
-                            + safe_end;
+                            .sum::<usize>();
+                        if annotation_start_col == annotation_end_col {
+                            // At least highlight something
+                            annotation_end_col += 1;
+                        }
 
                         span_left_margin = min(span_left_margin, annotation_start_col);
                         span_right_margin = max(span_right_margin, annotation_end_col);
diff --git a/tests/fixtures/no-color/ann_eof.svg b/tests/fixtures/no-color/ann_eof.svg
index ba3b204..c8900d0 100644
--- a/tests/fixtures/no-color/ann_eof.svg
+++ b/tests/fixtures/no-color/ann_eof.svg
@@ -24,7 +24,7 @@
 </tspan>
     <tspan x="10px" y="82px"><tspan>1 | asdf</tspan>
 </tspan>
-    <tspan x="10px" y="100px"><tspan>  |     </tspan>
+    <tspan x="10px" y="100px"><tspan>  |     ^</tspan>
 </tspan>
     <tspan x="10px" y="118px"><tspan>  |</tspan>
 </tspan>
diff --git a/tests/fixtures/no-color/ann_insertion.svg b/tests/fixtures/no-color/ann_insertion.svg
index ba3b204..b15b81b 100644
--- a/tests/fixtures/no-color/ann_insertion.svg
+++ b/tests/fixtures/no-color/ann_insertion.svg
@@ -18,13 +18,13 @@
   <text xml:space="preserve" class="container fg">
     <tspan x="10px" y="28px"><tspan>error: expected `.`, `=`</tspan>
 </tspan>
-    <tspan x="10px" y="46px"><tspan> --&gt; Cargo.toml:1:5</tspan>
+    <tspan x="10px" y="46px"><tspan> --&gt; Cargo.toml:1:3</tspan>
 </tspan>
     <tspan x="10px" y="64px"><tspan>  |</tspan>
 </tspan>
-    <tspan x="10px" y="82px"><tspan>1 | asdf</tspan>
+    <tspan x="10px" y="82px"><tspan>1 | asf</tspan>
 </tspan>
-    <tspan x="10px" y="100px"><tspan>  |     </tspan>
+    <tspan x="10px" y="100px"><tspan>  |   ^ 'd' belongs here</tspan>
 </tspan>
     <tspan x="10px" y="118px"><tspan>  |</tspan>
 </tspan>