Adding test to verify code block idempotency in Configurations.md

Author: davidalber

Cargo.lock

@@ -45,6 +45,9 @@ getopts = "0.2"
 derive-new = "0.5"
 cargo_metadata = "0.4"
 
+[dev-dependencies]
+lazy_static = "1.0.0"
+
 [target.'cfg(unix)'.dependencies]
 libc = "0.2.11"
 

Cargo.toml

@@ -511,12 +511,12 @@ Maximum length of comments. No effect unless`wrap_comments = true`.
 
 **Note:** A value of `0` results in [`wrap_comments`](#wrap_comments) being applied regardless of a line's width.
 
-#### Comments shorter than `comment_width`:
+#### `80` (default; comments shorter than `comment_width`):
 ```rust
 // Lorem ipsum dolor sit amet, consectetur adipiscing elit.
 ```
 
-#### Comments longer than `comment_width`:
+#### `60` (comments longer than `comment_width`):
 ```rust
 // Lorem ipsum dolor sit amet,
 // consectetur adipiscing elit.

Configurations.md

@@ -97,15 +97,28 @@ pub fn make_diff(expected: &str, actual: &str, context_size: usize) -> Vec<Misma
     results
 }
 
+// A representation of how to write output.
+pub enum PrintType {
+    Fancy, // want to output color and the terminal supports it
+    Basic, // do not want to output color or the terminal does not support color
+}
+
+impl PrintType {
+    pub fn get(color: Color) -> Self {
+        match term::stdout() {
+            Some(ref t) if use_colored_tty(color) && t.supports_color() => PrintType::Fancy,
+            _ => PrintType::Basic,
+        }
+    }
+}
+
 pub fn print_diff<F>(diff: Vec<Mismatch>, get_section_title: F, color: Color)
 where
     F: Fn(u32) -> String,
 {
-    match term::stdout() {
-        Some(ref t) if use_colored_tty(color) && t.supports_color() => {
-            print_diff_fancy(diff, get_section_title, term::stdout().unwrap())
-        }
-        _ => print_diff_basic(diff, get_section_title),
+    match PrintType::get(color) {
+        PrintType::Fancy => print_diff_fancy(diff, get_section_title, term::stdout().unwrap()),
+        PrintType::Basic => print_diff_basic(diff, get_section_title),
     }
 }