1 files changed, 289 insertions, 0 deletions
diff --git a/cli/fmt_errors.rs b/cli/fmt_errors.rs
new file mode 100644
index 000000000..957e799ca
--- /dev/null
+++ b/cli/fmt_errors.rs
@@ -0,0 +1,289 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+//! This mod provides DenoError to unify errors across Deno.
+use crate::ansi;
+use deno::JSError;
+use deno::StackFrame;
+use std::fmt;
+
+/// A trait which specifies parts of a diagnostic like item needs to be able to
+/// generate to conform its display to other diagnostic like items
+pub trait DisplayFormatter {
+  fn format_category_and_code(&self) -> String;
+  fn format_message(&self, level: usize) -> String;
+  fn format_related_info(&self) -> String;
+  fn format_source_line(&self, level: usize) -> String;
+  fn format_source_name(&self) -> String;
+}
+
+fn format_source_name(script_name: String, line: i64, column: i64) -> String {
+  let script_name_c = ansi::cyan(script_name);
+  let line_c = ansi::yellow((1 + line).to_string());
+  let column_c = ansi::yellow((1 + column).to_string());
+  format!("{}:{}:{}", script_name_c, line_c, column_c,)
+}
+
+/// Formats optional source, line and column into a single string.
+pub fn format_maybe_source_name(
+  script_name: Option<String>,
+  line: Option<i64>,
+  column: Option<i64>,
+) -> String {
+  if script_name.is_none() {
+    return "".to_string();
+  }
+
+  assert!(line.is_some());
+  assert!(column.is_some());
+  format_source_name(script_name.unwrap(), line.unwrap(), column.unwrap())
+}
+
+/// Take an optional source line and associated information to format it into
+/// a pretty printed version of that line.
+pub fn format_maybe_source_line(
+  source_line: Option<String>,
+  line_number: Option<i64>,
+  start_column: Option<i64>,
+  end_column: Option<i64>,
+  is_error: bool,
+  level: usize,
+) -> String {
+  if source_line.is_none() || line_number.is_none() {
+    return "".to_string();
+  }
+
+  let source_line = source_line.as_ref().unwrap();
+  // sometimes source_line gets set with an empty string, which then outputs
+  // an empty source line when displayed, so need just short circuit here
+  if source_line.is_empty() {
+    return "".to_string();
+  }
+
+  assert!(start_column.is_some());
+  assert!(end_column.is_some());
+  let line = (1 + line_number.unwrap()).to_string();
+  let line_color = ansi::black_on_white(line.to_string());
+  let line_len = line.clone().len();
+  let line_padding =
+    ansi::black_on_white(format!("{:indent$}", "", indent = line_len))
+      .to_string();
+  let mut s = String::new();
+  let start_column = start_column.unwrap();
+  let end_column = end_column.unwrap();
+  // TypeScript uses `~` always, but V8 would utilise `^` always, even when
+  // doing ranges, so here, if we only have one marker (very common with V8
+  // errors) we will use `^` instead.
+  let underline_char = if (end_column - start_column) <= 1 {
+    '^'
+  } else {
+    '~'
+  };
+  for i in 0..end_column {
+    if i >= start_column {
+      s.push(underline_char);
+    } else {
+      s.push(' ');
+    }
+  }
+  let color_underline = if is_error {
+    ansi::red(s).to_string()
+  } else {
+    ansi::cyan(s).to_string()
+  };
+
+  let indent = format!("{:indent$}", "", indent = level);
+
+  format!(
+    "\n\n{}{} {}\n{}{} {}\n",
+    indent, line_color, source_line, indent, line_padding, color_underline
+  )
+}
+
+/// Format a message to preface with `error: ` with ansi codes for red.
+pub fn format_error_message(msg: String) -> String {
+  let preamble = ansi::red("error:".to_string());
+  format!("{} {}", preamble, msg)
+}
+
+/// Wrapper around JSError which provides color to_string.
+pub struct JSErrorColor<'a>(pub &'a JSError);
+
+impl<'a> DisplayFormatter for JSErrorColor<'a> {
+  fn format_category_and_code(&self) -> String {
+    "".to_string()
+  }
+
+  fn format_message(&self, _level: usize) -> String {
+    format!(
+      "{}{}",
+      ansi::red_bold("error: ".to_string()),
+      self.0.message.clone()
+    )
+  }
+
+  fn format_related_info(&self) -> String {
+    "".to_string()
+  }
+
+  fn format_source_line(&self, level: usize) -> String {
+    format_maybe_source_line(
+      self.0.source_line.clone(),
+      self.0.line_number,
+      self.0.start_column,
+      self.0.end_column,
+      true,
+      level,
+    )
+  }
+
+  fn format_source_name(&self) -> String {
+    let e = self.0;
+    if e.script_resource_name.is_none() {
+      return "".to_string();
+    }
+
+    format!(
+      "\n► {}",
+      format_maybe_source_name(
+        e.script_resource_name.clone(),
+        e.line_number,
+        e.start_column,
+      )
+    )
+  }
+}
+
+impl<'a> fmt::Display for JSErrorColor<'a> {
+  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    write!(
+      f,
+      "{}{}{}",
+      self.format_message(0),
+      self.format_source_name(),
+      self.format_source_line(0),
+    )?;
+
+    for frame in &self.0.frames {
+      write!(f, "\n{}", StackFrameColor(&frame).to_string())?;
+    }
+    Ok(())
+  }
+}
+
+struct StackFrameColor<'a>(&'a StackFrame);
+
+impl<'a> fmt::Display for StackFrameColor<'a> {
+  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    let frame = self.0;
+    // Note when we print to string, we change from 0-indexed to 1-indexed.
+    let function_name = ansi::italic_bold(frame.function_name.clone());
+    let script_line_column =
+      format_source_name(frame.script_name.clone(), frame.line, frame.column);
+
+    if !frame.function_name.is_empty() {
+      write!(f, "    at {} ({})", function_name, script_line_column)
+    } else if frame.is_eval {
+      write!(f, "    at eval ({})", script_line_column)
+    } else {
+      write!(f, "    at {}", script_line_column)
+    }
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+  use crate::ansi::strip_ansi_codes;
+
+  fn error1() -> JSError {
+    JSError {
+      message: "Error: foo bar".to_string(),
+      source_line: None,
+      script_resource_name: None,
+      line_number: None,
+      start_position: None,
+      end_position: None,
+      error_level: None,
+      start_column: None,
+      end_column: None,
+      frames: vec![
+        StackFrame {
+          line: 4,
+          column: 16,
+          script_name: "foo_bar.ts".to_string(),
+          function_name: "foo".to_string(),
+          is_eval: false,
+          is_constructor: false,
+          is_wasm: false,
+        },
+        StackFrame {
+          line: 5,
+          column: 20,
+          script_name: "bar_baz.ts".to_string(),
+          function_name: "qat".to_string(),
+          is_eval: false,
+          is_constructor: false,
+          is_wasm: false,
+        },
+        StackFrame {
+          line: 1,
+          column: 1,
+          script_name: "deno_main.js".to_string(),
+          function_name: "".to_string(),
+          is_eval: false,
+          is_constructor: false,
+          is_wasm: false,
+        },
+      ],
+    }
+  }
+
+  #[test]
+  fn js_error_to_string() {
+    let e = error1();
+    assert_eq!("error: Error: foo bar\n    at foo (foo_bar.ts:5:17)\n    at qat (bar_baz.ts:6:21)\n    at deno_main.js:2:2", strip_ansi_codes(&JSErrorColor(&e).to_string()));
+  }
+
+  #[test]
+  fn test_format_none_source_name() {
+    let actual = format_maybe_source_name(None, None, None);
+    assert_eq!(actual, "");
+  }
+
+  #[test]
+  fn test_format_some_source_name() {
+    let actual = format_maybe_source_name(
+      Some("file://foo/bar.ts".to_string()),
+      Some(1),
+      Some(2),
+    );
+    assert_eq!(strip_ansi_codes(&actual), "file://foo/bar.ts:2:3");
+  }
+
+  #[test]
+  fn test_format_none_source_line() {
+    let actual = format_maybe_source_line(None, None, None, None, false, 0);
+    assert_eq!(actual, "");
+  }
+
+  #[test]
+  fn test_format_some_source_line() {
+    let actual = format_maybe_source_line(
+      Some("console.log('foo');".to_string()),
+      Some(8),
+      Some(8),
+      Some(11),
+      true,
+      0,
+    );
+    assert_eq!(
+      strip_ansi_codes(&actual),
+      "\n\n9 console.log(\'foo\');\n          ~~~\n"
+    );
+  }
+
+  #[test]
+  fn test_format_error_message() {
+    let actual = format_error_message("foo".to_string());
+    assert_eq!(strip_ansi_codes(&actual), "error: foo");
+  }
+}