fix(printer): Show snippet message for unnamed sources (#39)

Fixes: https://github.com/zkat/miette/issues/38

src/printer/graphical_printer.rs

@@ -189,23 +189,29 @@ impl GraphicalReportPrinter {
             .len();
 
         // Header
+        write!(
+            f,
+            "{}{}{}",
+            " ".repeat(linum_width + 2),
+            self.theme.characters.ltop,
+            self.theme.characters.hbar.to_string().repeat(3),
+        )?;
         if let Some(source_name) = snippet.source.name() {
             let source_name = source_name.style(self.theme.styles.filename);
             write!(
                 f,
-                "{}{}{}[{}:{}:{}]",
+                "[{}:{}:{}]",
-                " ".repeat(linum_width + 2),
-                self.theme.characters.ltop,
-                self.theme.characters.hbar.to_string().repeat(3),
                 source_name,
                 contents.line() + 1,
                 contents.column() + 1
             )?;
-            if let Some(msg) = &snippet.message {
+        } else {
-                write!(f, " {}:", msg)?;
+            write!(f, "[{}:{}]", contents.line() + 1, contents.column() + 1)?;
-            }
-            writeln!(f)?;
         }
+        if let Some(msg) = &snippet.message {
+            write!(f, " {}:", msg)?;
+        }
+        writeln!(f)?;
 
         // Now it's time for the fun part--actually rendering everything!
         for line in &lines {

src/printer/narratable_printer.rs

@@ -93,12 +93,16 @@ impl NarratableReportPrinter {
         if let Some(filename) = snippet.source.name() {
             write!(f, " for {}", filename,)?;
         }
-        writeln!(
+        write!(
             f,
             " starting at line {}, column {}",
             contents.line() + 1,
             contents.column() + 1
         )?;
+        if let Some(message) = snippet.message.as_deref() {
+            write!(f, ": {}", message)?;
+        }
+        writeln!(f)?;
         writeln!(f)?;
 
         // Highlights are the bits we're going to underline in our overall

tests/narrated.rs

@@ -45,7 +45,7 @@ fn single_line_highlight() -> Result<(), MietteError> {
 oops!
     Diagnostic severity: error
 
-Begin snippet for bad_file.rs starting at line 1, column 1
+Begin snippet for bad_file.rs starting at line 1, column 1: This is the part that broke
 
 snippet line 1: source
 snippet line 2:   text
@@ -87,7 +87,7 @@ fn single_line_highlight_no_label() -> Result<(), MietteError> {
 oops!
     Diagnostic severity: error
 
-Begin snippet for bad_file.rs starting at line 1, column 1
+Begin snippet for bad_file.rs starting at line 1, column 1: This is the part that broke
 
 snippet line 1: source
 snippet line 2:   text
@@ -132,7 +132,7 @@ fn multiple_same_line_highlights() -> Result<(), MietteError> {
 oops!
     Diagnostic severity: error
 
-Begin snippet for bad_file.rs starting at line 1, column 1
+Begin snippet for bad_file.rs starting at line 1, column 1: This is the part that broke
 
 snippet line 1: source
 snippet line 2:   text text text text text
@@ -175,7 +175,7 @@ fn multiline_highlight_adjacent() -> Result<(), MietteError> {
 oops!
     Diagnostic severity: error
 
-Begin snippet for bad_file.rs starting at line 1, column 1
+Begin snippet for bad_file.rs starting at line 1, column 1: This is the part that broke
 
 snippet line 1: source
 snippet line 2:   text
@@ -226,7 +226,7 @@ line5
 oops!
     Diagnostic severity: error
 
-Begin snippet for bad_file.rs starting at line 1, column 1
+Begin snippet for bad_file.rs starting at line 1, column 1: This is the part that broke
 
 snippet line 1: line1
     highlight starting at line 1, column 1: block 1
@@ -280,7 +280,7 @@ line5
 oops!
     Diagnostic severity: error
 
-Begin snippet for bad_file.rs starting at line 1, column 1
+Begin snippet for bad_file.rs starting at line 1, column 1: This is the part that broke
 
 snippet line 1: line1
     highlight starting at line 1, column 1: block 1
@@ -328,7 +328,7 @@ fn multiple_multiline_highlights_adjacent() -> Result<(), MietteError> {
 oops!
     Diagnostic severity: error
 
-Begin snippet for bad_file.rs starting at line 1, column 1
+Begin snippet for bad_file.rs starting at line 1, column 1: This is the part that broke
 
 snippet line 1: source
     highlight starting at line 1, column 1: this bit here
@@ -377,7 +377,7 @@ fn multiple_multiline_highlights_overlapping_lines() -> Result<(), MietteError>
 oops!
     Diagnostic severity: error
 
-Begin snippet for bad_file.rs starting at line 1, column 1
+Begin snippet for bad_file.rs starting at line 1, column 1: This is the part that broke
 
 snippet line 1: source
     highlight starting at line 1, column 1: this bit here
@@ -441,3 +441,36 @@ diagnostic error code: oops::my::bad
     assert_eq!(expected, out);
     Ok(())
 }
+
+#[test]
+fn unnamed_snippet_shows_message() {
+    #[derive(Debug, Diagnostic, Error)]
+    #[error("oops!")]
+    #[diagnostic(code(oops::my::bad), help("try doing it better next time?"))]
+    struct MyBad {
+        src: String,
+        #[snippet(src, message("This is the part that broke"))]
+        ctx: SourceSpan,
+    }
+    let src = "source_text_here".to_string();
+    let len = src.len();
+    let err = MyBad {
+        src,
+        ctx: (0, len).into(),
+    };
+    let out = fmt_report(err.into());
+    println!("{}", out);
+    let expected = r#"
+oops!
+    Diagnostic severity: error
+
+Begin snippet starting at line 1, column 1: This is the part that broke
+
+snippet line 1: source_text_here
+
+diagnostic help: try doing it better next time?
+diagnostic error code: oops::my::bad
+"#
+    .trim_start();
+    assert_eq!(out, expected);
+}

tests/printer.rs

@@ -491,3 +491,35 @@ fn disable_url_links() -> Result<(), MietteError> {
     assert!(out.contains("oops::my::bad"));
     Ok(())
 }
+
+#[test]
+fn unnamed_snippet_shows_message() {
+    #[derive(Debug, Diagnostic, Error)]
+    #[error("oops!")]
+    #[diagnostic(code(oops::my::bad), help("try doing it better next time?"))]
+    struct MyBad {
+        src: String,
+        #[snippet(src, message("This is the part that broke"))]
+        ctx: SourceSpan,
+    }
+    let src = "source_text_here".to_string();
+    let len = src.len();
+    let err = MyBad {
+        src,
+        ctx: (0, len).into(),
+    };
+    let out = fmt_report(err.into());
+    println!("{}", out);
+    let expected = r#"
+────[oops::my::bad]────────────────────
+
+    × oops!
+
+   ╭───[1:1] This is the part that broke:
+ 1 │ source_text_here
+
+    ‽ try doing it better next time?
+"#
+    .trim_start();
+    assert_eq!(out, expected);
+}