test(bf-5dopl): update unmapped glyph assertions in unmapped.rs

- Updated 9 assertion messages to reference build/unmapped-glyph-names.json
- Added detailed context about slash prefix handling
- Enhanced explanations for valid vs unmapped glyph detection
- Applied bf-w1o10 message design template

Closes bead: bf-5dopl (partial)

crates/pdftract-core/src/font/unmapped.rs

@@ -23,10 +23,34 @@ include!(concat!(env!("OUT_DIR"), "/unmapped_glyph_names.rs"));
 /// ```
 /// use pdftract_core::font::unmapped::is_unmapped_glyph_name;
 ///
-/// assert!(is_unmapped_glyph_name(".notdef"));
+/// assert!(
-/// assert!(is_unmapped_glyph_name("/.notdef"));
+///     is_unmapped_glyph_name(".notdef"),
-/// assert!(!is_unmapped_glyph_name("A"));
+///     ".notdef should be recognized as an unmapped glyph name. \
-/// assert!(!is_unmapped_glyph_name("space"));
+///      Expected: is_unmapped_glyph_name(\".notdef\") == true. \
+///      Found: false. \
+///      Why this matters: .notdef is a standard PDF special glyph defined in build/unmapped-glyph-names.json that should never appear in text extraction output.",
+/// );
+/// assert!(
+///     is_unmapped_glyph_name("/.notdef"),
+///     "/.notdef (with leading slash) should be recognized as an unmapped glyph name. \
+///      Expected: is_unmapped_glyph_name(\"/.notdef\") == true. \
+///      Found: false. \
+///      Why this matters: The function should handle glyph names both with and without leading slash, as defined in build/unmapped-glyph-names.json.",
+/// );
+/// assert!(
+///     !is_unmapped_glyph_name("A"),
+///     "Normal glyph 'A' should not be recognized as unmapped. \
+///      Expected: is_unmapped_glyph_name(\"A\") == false. \
+///      Found: true. \
+///      Why this matters: Letter glyphs are valid Unicode characters that should appear in text extraction output and should not be filtered by unmapped glyph detection.",
+/// );
+/// assert!(
+///     !is_unmapped_glyph_name("space"),
+///     "Normal glyph 'space' should not be recognized as unmapped. \
+///      Expected: is_unmapped_glyph_name(\"space\") == false. \
+///      Found: true. \
+///      Why this matters: space is a valid whitespace character that should appear in text extraction output for proper word separation.",
+/// );
 /// ```
 pub fn is_unmapped_glyph_name(name: &str) -> bool {
     // Strip leading slash if present
@@ -49,14 +73,14 @@ mod tests {
             ".notdef should be recognized as an unmapped glyph name. \
              Expected: is_unmapped_glyph_name(\".notdef\") == true. \
              Found: false. \
-             Why this matters: .notdef is a standard PDF special glyph that should never appear in text extraction output.",
+             Why this matters: .notdef is a standard PDF special glyph defined in build/unmapped-glyph-names.json that should never appear in text extraction output.",
         );
         assert!(
             is_unmapped_glyph_name("/.notdef"),
             "/.notdef (with leading slash) should be recognized as an unmapped glyph name. \
              Expected: is_unmapped_glyph_name(\"/.notdef\") == true. \
              Found: false. \
-             Why this matters: The function should handle glyph names both with and without leading slash.",
+             Why this matters: The function should handle glyph names both with and without leading slash, as defined in build/unmapped-glyph-names.json.",
         );
     }
 
@@ -67,42 +91,42 @@ mod tests {
             "Normal glyph 'A' should not be recognized as unmapped. \
              Expected: is_unmapped_glyph_name(\"A\") == false. \
              Found: true. \
-             Why this matters: Letter glyphs are valid Unicode characters and should not be filtered.",
+             Why this matters: Letter glyphs are valid Unicode characters that should appear in text extraction output and should not be filtered by unmapped glyph detection.",
         );
         assert!(
             !is_unmapped_glyph_name("/A"),
             "Normal glyph '/A' (with leading slash) should not be recognized as unmapped. \
              Expected: is_unmapped_glyph_name(\"/A\") == false. \
              Found: true. \
-             Why this matters: The function should handle normal glyph names both with and without leading slash.",
+             Why this matters: The function should handle normal glyph names both with and without leading slash, and should not falsely flag valid letters.",
         );
         assert!(
             !is_unmapped_glyph_name("space"),
             "Normal glyph 'space' should not be recognized as unmapped. \
              Expected: is_unmapped_glyph_name(\"space\") == false. \
              Found: true. \
-             Why this matters: space is a valid whitespace character that should appear in text extraction output.",
+             Why this matters: space is a valid whitespace character that should appear in text extraction output for proper word separation.",
         );
         assert!(
             !is_unmapped_glyph_name("/space"),
             "Normal glyph '/space' (with leading slash) should not be recognized as unmapped. \
              Expected: is_unmapped_glyph_name(\"/space\") == false. \
              Found: true. \
-             Why this matters: Whitespace glyphs are valid and should not be filtered.",
+             Why this matters: Whitespace glyphs are valid and should not be filtered, regardless of slash prefix presence.",
         );
         assert!(
             !is_unmapped_glyph_name("uni0041"),
             "Normal glyph 'uni0041' should not be recognized as unmapped. \
              Expected: is_unmapped_glyph_name(\"uni0041\") == false. \
              Found: true. \
-             Why this matters: uniXXXX format represents valid Unicode characters and should not be filtered.",
+             Why this matters: uniXXXX format represents valid Unicode characters (U+XXXX) and should not be filtered by unmapped glyph detection.",
         );
         assert!(
             !is_unmapped_glyph_name("/uni0041"),
             "Normal glyph '/uni0041' (with leading slash) should not be recognized as unmapped. \
              Expected: is_unmapped_glyph_name(\"/uni0041\") == false. \
              Found: true. \
-             Why this matters: The function should handle uniXXXX names both with and without leading slash.",
+             Why this matters: The function should handle uniXXXX names both with and without leading slash, as these represent valid Unicode code points.",
         );
     }
 
@@ -113,7 +137,7 @@ mod tests {
             "UNMAPPED_GLYPH_NAMES set should contain '.notdef'. \
              Expected: UNMAPPED_GLYPH_NAMES.contains(\".notdef\") == true. \
              Found: false. \
-             Why this matters: .notdef is a core unmapped glyph defined in build/unmapped-glyph-names.json configuration.",
+             Why this matters: .notdef is a core unmapped glyph defined in build/unmapped-glyph-names.json configuration and must be present in the runtime set for proper filtering.",
         );
     }
 }