Vendor dependencies

Let's see how I like this workflow.

vendor/codespan-reporting/tests/support/mod.rs

@@ -0,0 +1,31 @@
+use codespan_reporting::diagnostic::Diagnostic;
+use codespan_reporting::files::Files;
+use codespan_reporting::term::{emit, Config};
+use termcolor::{Buffer, WriteColor};
+
+mod color_buffer;
+
+use self::color_buffer::ColorBuffer;
+
+pub struct TestData<'files, F: Files<'files>> {
+    pub files: F,
+    pub diagnostics: Vec<Diagnostic<F::FileId>>,
+}
+
+impl<'files, F: Files<'files>> TestData<'files, F> {
+    fn emit<W: WriteColor>(&'files self, mut writer: W, config: &Config) -> W {
+        for diagnostic in &self.diagnostics {
+            emit(&mut writer, config, &self.files, &diagnostic).unwrap();
+        }
+        writer
+    }
+
+    pub fn emit_color(&'files self, config: &Config) -> String {
+        self.emit(ColorBuffer::new(), &config).into_string()
+    }
+
+    pub fn emit_no_color(&'files self, config: &Config) -> String {
+        let buffer = self.emit(Buffer::no_color(), &config);
+        String::from_utf8_lossy(buffer.as_slice()).into_owned()
+    }
+}