1 files changed, 416 insertions, 0 deletions
diff --git a/core/js_errors.rs b/core/js_errors.rs
new file mode 100644
index 000000000..c07af136f
--- /dev/null
+++ b/core/js_errors.rs
@@ -0,0 +1,416 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+
+// Note that source_map_mappings requires 0-indexed line and column numbers but
+// V8 Exceptions are 1-indexed.
+
+// TODO: This currently only applies to uncaught exceptions. It would be nice to
+// also have source maps for situations like this:
+//   const err = new Error("Boo!");
+//   console.log(err.stack);
+// It would require calling into Rust from Error.prototype.prepareStackTrace.
+
+use serde_json;
+use std::fmt;
+use std::str;
+
+#[derive(Debug, PartialEq)]
+pub struct StackFrame {
+  pub line: i64,   // zero indexed
+  pub column: i64, // zero indexed
+  pub script_name: String,
+  pub function_name: String,
+  pub is_eval: bool,
+  pub is_constructor: bool,
+  pub is_wasm: bool,
+}
+
+#[derive(Debug, PartialEq)]
+pub struct JSError {
+  pub message: String,
+
+  pub source_line: Option<String>,
+  pub script_resource_name: Option<String>,
+  pub line_number: Option<i64>,
+  pub start_position: Option<i64>,
+  pub end_position: Option<i64>,
+  pub error_level: Option<i64>,
+  pub start_column: Option<i64>,
+  pub end_column: Option<i64>,
+
+  pub frames: Vec<StackFrame>,
+}
+
+impl fmt::Display for StackFrame {
+  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    // Note when we print to string, we change from 0-indexed to 1-indexed.
+    let function_name = self.function_name.clone();
+    let script_line_column =
+      format_script_line_column(&self.script_name, self.line, self.column);
+
+    if !self.function_name.is_empty() {
+      write!(f, "    at {} ({})", function_name, script_line_column)
+    } else if self.is_eval {
+      write!(f, "    at eval ({})", script_line_column)
+    } else {
+      write!(f, "    at {}", script_line_column)
+    }
+  }
+}
+
+fn format_script_line_column(
+  script_name: &str,
+  line: i64,
+  column: i64,
+) -> String {
+  // TODO match this style with how typescript displays errors.
+  let line = (1 + line).to_string();
+  let column = (1 + column).to_string();
+  let script_name = script_name.to_string();
+  format!("{}:{}:{}", script_name, line, column)
+}
+
+impl fmt::Display for JSError {
+  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    if self.script_resource_name.is_some() {
+      let script_resource_name = self.script_resource_name.as_ref().unwrap();
+      // Avoid showing internal code from gen/bundle/main.js
+      if script_resource_name != "gen/bundle/main.js"
+        && script_resource_name != "gen/bundle/compiler.js"
+      {
+        if self.line_number.is_some() && self.start_column.is_some() {
+          assert!(self.line_number.is_some());
+          assert!(self.start_column.is_some());
+          let script_line_column = format_script_line_column(
+            script_resource_name,
+            self.line_number.unwrap() - 1,
+            self.start_column.unwrap() - 1,
+          );
+          write!(f, "{}", script_line_column)?;
+        }
+        if self.source_line.is_some() {
+          write!(f, "\n{}\n", self.source_line.as_ref().unwrap())?;
+          let mut s = String::new();
+          for i in 0..self.end_column.unwrap() {
+            if i >= self.start_column.unwrap() {
+              s.push('^');
+            } else {
+              s.push(' ');
+            }
+          }
+          writeln!(f, "{}", s)?;
+        }
+      }
+    }
+
+    write!(f, "{}", self.message.clone())?;
+
+    for frame in &self.frames {
+      write!(f, "\n{}", &frame.to_string())?;
+    }
+    Ok(())
+  }
+}
+
+impl StackFrame {
+  // TODO Maybe use serde_derive?
+  fn from_json_value(v: &serde_json::Value) -> Option<Self> {
+    if !v.is_object() {
+      return None;
+    }
+    let obj = v.as_object().unwrap();
+
+    let line_v = &obj["line"];
+    if !line_v.is_u64() {
+      return None;
+    }
+    let line = line_v.as_u64().unwrap() as i64;
+
+    let column_v = &obj["column"];
+    if !column_v.is_u64() {
+      return None;
+    }
+    let column = column_v.as_u64().unwrap() as i64;
+
+    let script_name_v = &obj["scriptName"];
+    if !script_name_v.is_string() {
+      return None;
+    }
+    let script_name = String::from(script_name_v.as_str().unwrap());
+
+    // Optional fields. See EncodeExceptionAsJSON() in libdeno.
+    // Sometimes V8 doesn't provide all the frame information.
+
+    let mut function_name = String::from(""); // default
+    if obj.contains_key("functionName") {
+      let function_name_v = &obj["functionName"];
+      if function_name_v.is_string() {
+        function_name = String::from(function_name_v.as_str().unwrap());
+      }
+    }
+
+    let mut is_eval = false; // default
+    if obj.contains_key("isEval") {
+      let is_eval_v = &obj["isEval"];
+      if is_eval_v.is_boolean() {
+        is_eval = is_eval_v.as_bool().unwrap();
+      }
+    }
+
+    let mut is_constructor = false; // default
+    if obj.contains_key("isConstructor") {
+      let is_constructor_v = &obj["isConstructor"];
+      if is_constructor_v.is_boolean() {
+        is_constructor = is_constructor_v.as_bool().unwrap();
+      }
+    }
+
+    let mut is_wasm = false; // default
+    if obj.contains_key("isWasm") {
+      let is_wasm_v = &obj["isWasm"];
+      if is_wasm_v.is_boolean() {
+        is_wasm = is_wasm_v.as_bool().unwrap();
+      }
+    }
+
+    Some(StackFrame {
+      line: line - 1,
+      column: column - 1,
+      script_name,
+      function_name,
+      is_eval,
+      is_constructor,
+      is_wasm,
+    })
+  }
+}
+
+impl JSError {
+  /// Creates a new JSError by parsing the raw exception JSON string from V8.
+  pub fn from_v8_exception(json_str: &str) -> Option<Self> {
+    let v = serde_json::from_str::<serde_json::Value>(json_str);
+    if v.is_err() {
+      return None;
+    }
+    let v = v.unwrap();
+
+    if !v.is_object() {
+      return None;
+    }
+    let obj = v.as_object().unwrap();
+
+    let message_v = &obj["message"];
+    if !message_v.is_string() {
+      return None;
+    }
+    let message = String::from(message_v.as_str().unwrap());
+
+    let source_line = obj
+      .get("sourceLine")
+      .and_then(|v| v.as_str().map(String::from));
+    let script_resource_name = obj
+      .get("scriptResourceName")
+      .and_then(|v| v.as_str().map(String::from));
+    let line_number = obj.get("lineNumber").and_then(|v| v.as_i64());
+    let start_position = obj.get("startPosition").and_then(|v| v.as_i64());
+    let end_position = obj.get("endPosition").and_then(|v| v.as_i64());
+    let error_level = obj.get("errorLevel").and_then(|v| v.as_i64());
+    let start_column = obj.get("startColumn").and_then(|v| v.as_i64());
+    let end_column = obj.get("endColumn").and_then(|v| v.as_i64());
+
+    let frames_v = &obj["frames"];
+    if !frames_v.is_array() {
+      return None;
+    }
+    let frame_values = frames_v.as_array().unwrap();
+
+    let mut frames = Vec::<StackFrame>::new();
+    for frame_v in frame_values {
+      match StackFrame::from_json_value(frame_v) {
+        None => return None,
+        Some(frame) => frames.push(frame),
+      }
+    }
+
+    Some(JSError {
+      message,
+      source_line,
+      script_resource_name,
+      line_number,
+      start_position,
+      end_position,
+      error_level,
+      start_column,
+      end_column,
+      frames,
+    })
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  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 stack_frame_from_json_value_1() {
+    let v = serde_json::from_str::<serde_json::Value>(
+      r#"{
+        "line":2,
+        "column":11,
+        "functionName":"foo",
+        "scriptName":"/Users/rld/src/deno/tests/error_001.ts",
+        "isEval":true,
+        "isConstructor":false,
+        "isWasm":false
+      }"#,
+    ).unwrap();
+    let r = StackFrame::from_json_value(&v);
+    assert_eq!(
+      r,
+      Some(StackFrame {
+        line: 1,
+        column: 10,
+        script_name: "/Users/rld/src/deno/tests/error_001.ts".to_string(),
+        function_name: "foo".to_string(),
+        is_eval: true,
+        is_constructor: false,
+        is_wasm: false,
+      })
+    );
+  }
+
+  #[test]
+  fn stack_frame_from_json_value_2() {
+    let v = serde_json::from_str::<serde_json::Value>(
+      r#"{
+        "scriptName": "/Users/rld/src/deno/tests/error_001.ts",
+        "line": 2,
+        "column": 11
+      }"#,
+    ).unwrap();
+    let r = StackFrame::from_json_value(&v);
+    assert!(r.is_some());
+    let f = r.unwrap();
+    assert_eq!(f.line, 1);
+    assert_eq!(f.column, 10);
+    assert_eq!(f.script_name, "/Users/rld/src/deno/tests/error_001.ts");
+  }
+
+  #[test]
+  fn js_error_from_v8_exception() {
+    let r = JSError::from_v8_exception(
+      r#"{
+        "message":"Uncaught Error: bad",
+        "frames":[
+          {
+            "line":2,
+            "column":11,
+            "functionName":"foo",
+            "scriptName":"/Users/rld/src/deno/tests/error_001.ts",
+            "isEval":true,
+            "isConstructor":false,
+            "isWasm":false
+          }, {
+            "line":5,
+            "column":5,
+            "functionName":"bar",
+            "scriptName":"/Users/rld/src/deno/tests/error_001.ts",
+            "isEval":true,
+            "isConstructor":false,
+            "isWasm":false
+          }
+        ]}"#,
+    );
+    assert!(r.is_some());
+    let e = r.unwrap();
+    assert_eq!(e.message, "Uncaught Error: bad");
+    assert_eq!(e.frames.len(), 2);
+    assert_eq!(
+      e.frames[0],
+      StackFrame {
+        line: 1,
+        column: 10,
+        script_name: "/Users/rld/src/deno/tests/error_001.ts".to_string(),
+        function_name: "foo".to_string(),
+        is_eval: true,
+        is_constructor: false,
+        is_wasm: false,
+      }
+    )
+  }
+
+  #[test]
+  fn js_error_from_v8_exception2() {
+    let r = JSError::from_v8_exception(
+      "{\"message\":\"Error: boo\",\"sourceLine\":\"throw Error('boo');\",\"scriptResourceName\":\"a.js\",\"lineNumber\":3,\"startPosition\":8,\"endPosition\":9,\"errorLevel\":8,\"startColumn\":6,\"endColumn\":7,\"isSharedCrossOrigin\":false,\"isOpaque\":false,\"frames\":[{\"line\":3,\"column\":7,\"functionName\":\"\",\"scriptName\":\"a.js\",\"isEval\":false,\"isConstructor\":false,\"isWasm\":false}]}"
+    );
+    assert!(r.is_some());
+    let e = r.unwrap();
+    assert_eq!(e.message, "Error: boo");
+    assert_eq!(e.source_line, Some("throw Error('boo');".to_string()));
+    assert_eq!(e.script_resource_name, Some("a.js".to_string()));
+    assert_eq!(e.line_number, Some(3));
+    assert_eq!(e.start_position, Some(8));
+    assert_eq!(e.end_position, Some(9));
+    assert_eq!(e.error_level, Some(8));
+    assert_eq!(e.start_column, Some(6));
+    assert_eq!(e.end_column, Some(7));
+    assert_eq!(e.frames.len(), 1);
+  }
+
+  #[test]
+  fn stack_frame_to_string() {
+    let e = error1();
+    assert_eq!("    at foo (foo_bar.ts:5:17)", &e.frames[0].to_string());
+    assert_eq!("    at qat (bar_baz.ts:6:21)", &e.frames[1].to_string());
+  }
+
+  #[test]
+  fn js_error_to_string() {
+    let e = error1();
+    let expected = "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";
+    assert_eq!(expected, &e.to_string());
+  }
+}