add nu-ansi-term (#3089)

crates/nu-ansi-term/src/debug.rs

@@ -0,0 +1,152 @@
+use crate::style::Style;
+use std::fmt;
+
+/// Styles have a special `Debug` implementation that only shows the fields that
+/// are set. Fields that haven’t been touched aren’t included in the output.
+///
+/// This behaviour gets bypassed when using the alternate formatting mode
+/// `format!("{:#?}")`.
+///
+///     use nu_ansi_term::Color::{Red, Blue};
+///     assert_eq!("Style { fg(Red), on(Blue), bold, italic }",
+///                format!("{:?}", Red.on(Blue).bold().italic()));
+impl fmt::Debug for Style {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        if fmt.alternate() {
+            fmt.debug_struct("Style")
+                .field("foreground", &self.foreground)
+                .field("background", &self.background)
+                .field("blink", &self.is_blink)
+                .field("bold", &self.is_bold)
+                .field("dimmed", &self.is_dimmed)
+                .field("hidden", &self.is_hidden)
+                .field("italic", &self.is_italic)
+                .field("reverse", &self.is_reverse)
+                .field("strikethrough", &self.is_strikethrough)
+                .field("underline", &self.is_underline)
+                .finish()
+        } else if self.is_plain() {
+            fmt.write_str("Style {}")
+        } else {
+            fmt.write_str("Style { ")?;
+
+            let mut written_anything = false;
+
+            if let Some(fg) = self.foreground {
+                if written_anything {
+                    fmt.write_str(", ")?
+                }
+                written_anything = true;
+                write!(fmt, "fg({:?})", fg)?
+            }
+
+            if let Some(bg) = self.background {
+                if written_anything {
+                    fmt.write_str(", ")?
+                }
+                written_anything = true;
+                write!(fmt, "on({:?})", bg)?
+            }
+
+            {
+                let mut write_flag = |name| {
+                    if written_anything {
+                        fmt.write_str(", ")?
+                    }
+                    written_anything = true;
+                    fmt.write_str(name)
+                };
+
+                if self.is_blink {
+                    write_flag("blink")?
+                }
+                if self.is_bold {
+                    write_flag("bold")?
+                }
+                if self.is_dimmed {
+                    write_flag("dimmed")?
+                }
+                if self.is_hidden {
+                    write_flag("hidden")?
+                }
+                if self.is_italic {
+                    write_flag("italic")?
+                }
+                if self.is_reverse {
+                    write_flag("reverse")?
+                }
+                if self.is_strikethrough {
+                    write_flag("strikethrough")?
+                }
+                if self.is_underline {
+                    write_flag("underline")?
+                }
+            }
+
+            write!(fmt, " }}")
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use crate::style::Color::*;
+    use crate::style::Style;
+
+    fn style() -> Style {
+        Style::new()
+    }
+
+    macro_rules! test {
+        ($name: ident: $obj: expr => $result: expr) => {
+            #[test]
+            fn $name() {
+                assert_eq!($result, format!("{:?}", $obj));
+            }
+        };
+    }
+
+    test!(empty:   style()                  => "Style {}");
+    test!(bold:    style().bold()           => "Style { bold }");
+    test!(italic:  style().italic()         => "Style { italic }");
+    test!(both:    style().bold().italic()  => "Style { bold, italic }");
+
+    test!(red:     Red.normal()                     => "Style { fg(Red) }");
+    test!(redblue: Red.normal().on(RGB(3, 2, 4))    => "Style { fg(Red), on(RGB(3, 2, 4)) }");
+
+    test!(everything:
+            Red.on(Blue).blink().bold().dimmed().hidden().italic().reverse().strikethrough().underline() =>
+            "Style { fg(Red), on(Blue), blink, bold, dimmed, hidden, italic, reverse, strikethrough, underline }");
+
+    #[test]
+    fn long_and_detailed() {
+        extern crate regex;
+        let expected_debug = "Style { fg(Blue), bold }";
+        let expected_pretty_repat = r##"(?x)
+        Style\s+\{\s+
+            foreground:\s+Some\(\s+
+                Blue,?\s+
+            \),\s+
+            background:\s+None,\s+
+            blink:\s+false,\s+
+            bold:\s+true,\s+
+            dimmed:\s+false,\s+
+            hidden:\s+false,\s+
+            italic:\s+false,\s+
+            reverse:\s+false,\s+
+            strikethrough:\s+
+            false,\s+
+            underline:\s+false,?\s+
+            \}"##;
+        let re = regex::Regex::new(expected_pretty_repat).unwrap();
+
+        let style = Blue.bold();
+        let style_fmt_debug = format!("{:?}", style);
+        let style_fmt_pretty = format!("{:#?}", style);
+        println!("style_fmt_debug:\n{}", style_fmt_debug);
+        println!("style_fmt_pretty:\n{}", style_fmt_pretty);
+
+        assert_eq!(expected_debug, style_fmt_debug);
+        assert!(re.is_match(&style_fmt_pretty));
+    }
+}