refactor: Move source map lookups to core (#14274)

The following transformations gradually faced by "JsError" have all been 
moved up front to "JsError::from_v8_exception()": 

- finding the first non-"deno:" source line; 
- moving "JsError::script_resource_name" etc. into the first error stack 
in case of syntax errors; 
- source mapping "JsError::script_resource_name" etc. when wrapping 
the error even though the frame locations are source mapped earlier; 
- removing "JsError::{script_resource_name,line_number,start_column,end_column}"
entirely in favour of "js_error.frames.get(0)". 

We also no longer pass a js-side callback to "core/02_error.js" from cli. 
I avoided doing this on previous occasions because the source map lookups 
were in an awkward place.

1 files changed, 0 insertions, 264 deletions

diff --git a/cli/source_maps.rs b/cli/source_maps.rs
deleted file mode 100644
index d92caf7f4..000000000
--- a/cli/source_maps.rs
+++ /dev/null
@@ -1,264 +0,0 @@
-// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
-
-//! This mod provides functions to remap a `JsError` based on a source map.
-
-use deno_core::error::JsError;
-use sourcemap::SourceMap;
-use std::collections::HashMap;
-use std::str;
-
-pub trait SourceMapGetter: Sync + Send + Clone {
-  /// Returns the raw source map file.
-  fn get_source_map(&self, file_name: &str) -> Option<Vec<u8>>;
-  fn get_source_line(
-    &self,
-    file_name: &str,
-    line_number: usize,
-  ) -> Option<String>;
-}
-
-/// Cached filename lookups. The key can be None if a previous lookup failed to
-/// find a SourceMap.
-pub type CachedMaps = HashMap<String, Option<SourceMap>>;
-
-/// Apply a source map to a `deno_core::JsError`, returning a `JsError` where
-/// file names and line/column numbers point to the location in the original
-/// source, rather than the transpiled source code.
-pub fn apply_source_map<G: SourceMapGetter>(
-  js_error: &JsError,
-  getter: G,
-) -> JsError {
-  // Note that js_error.frames has already been source mapped in
-  // prepareStackTrace().
-  let mut mappings_map: CachedMaps = HashMap::new();
-
-  let (script_resource_name, line_number, start_column, source_line) =
-    get_maybe_orig_position(
-      js_error.script_resource_name.clone(),
-      js_error.line_number,
-      // start_column is 0-based, we need 1-based here.
-      js_error.start_column.map(|n| n + 1),
-      &mut mappings_map,
-      getter.clone(),
-    );
-  let start_column = start_column.map(|n| n - 1);
-  // It is better to just move end_column to be the same distance away from
-  // start column because sometimes the code point is not available in the
-  // source file map.
-  let end_column = match js_error.end_column {
-    Some(ec) => {
-      start_column.map(|sc| ec - (js_error.start_column.unwrap() - sc))
-    }
-    _ => None,
-  };
-
-  let mut script_resource_name = script_resource_name;
-  let mut line_number = line_number;
-  let mut start_column = start_column;
-  let mut end_column = end_column;
-  let mut source_line = source_line;
-  if script_resource_name
-    .as_ref()
-    .map_or(true, |s| s.starts_with("deno:"))
-  {
-    for frame in &js_error.frames {
-      if let (Some(file_name), Some(line_number_)) =
-        (&frame.file_name, frame.line_number)
-      {
-        if !file_name.starts_with("deno:") {
-          script_resource_name = Some(file_name.clone());
-          line_number = Some(line_number_);
-          start_column = frame.column_number.map(|n| n - 1);
-          end_column = frame.column_number;
-          // Lookup expects 0-based line and column numbers, but ours are 1-based.
-          source_line =
-            getter.get_source_line(file_name, (line_number_ - 1) as usize);
-          break;
-        }
-      }
-    }
-  }
-
-  let cause = js_error
-    .cause
-    .clone()
-    .map(|cause| Box::new(apply_source_map(&*cause, getter)));
-
-  JsError {
-    name: js_error.name.clone(),
-    message: js_error.message.clone(),
-    exception_message: js_error.exception_message.clone(),
-    cause,
-    source_line,
-    script_resource_name,
-    line_number,
-    start_column,
-    end_column,
-    frames: js_error.frames.clone(),
-    stack: None,
-  }
-}
-
-fn get_maybe_orig_position<G: SourceMapGetter>(
-  file_name: Option<String>,
-  line_number: Option<i64>,
-  column_number: Option<i64>,
-  mappings_map: &mut CachedMaps,
-  getter: G,
-) -> (Option<String>, Option<i64>, Option<i64>, Option<String>) {
-  match (file_name, line_number, column_number) {
-    (Some(file_name_v), Some(line_v), Some(column_v)) => {
-      let (file_name, line_number, column_number, source_line) =
-        get_orig_position(file_name_v, line_v, column_v, mappings_map, getter);
-      (
-        Some(file_name),
-        Some(line_number),
-        Some(column_number),
-        source_line,
-      )
-    }
-    _ => (None, None, None, None),
-  }
-}
-
-pub fn get_orig_position<G: SourceMapGetter>(
-  file_name: String,
-  line_number: i64,
-  column_number: i64,
-  mappings_map: &mut CachedMaps,
-  getter: G,
-) -> (String, i64, i64, Option<String>) {
-  // Lookup expects 0-based line and column numbers, but ours are 1-based.
-  let line_number = line_number - 1;
-  let column_number = column_number - 1;
-
-  let default_pos = (file_name.clone(), line_number, column_number, None);
-  let maybe_source_map = get_mappings(&file_name, mappings_map, getter.clone());
-  let (file_name, line_number, column_number, source_line) =
-    match maybe_source_map {
-      None => default_pos,
-      Some(source_map) => {
-        match source_map.lookup_token(line_number as u32, column_number as u32)
-        {
-          None => default_pos,
-          Some(token) => match token.get_source() {
-            None => default_pos,
-            Some(source_file_name) => {
-              // The `source_file_name` written by tsc in the source map is
-              // sometimes only the basename of the URL, or has unwanted `<`/`>`
-              // around it. Use the `file_name` we get from V8 if
-              // `source_file_name` does not parse as a URL.
-              let file_name = match deno_core::resolve_url(source_file_name) {
-                Ok(m) if m.scheme() == "blob" => file_name,
-                Ok(m) => m.to_string(),
-                Err(_) => file_name,
-              };
-              let source_line =
-                if let Some(source_view) = token.get_source_view() {
-                  source_view
-                    .get_line(token.get_src_line())
-                    .map(|s| s.to_string())
-                } else {
-                  None
-                };
-              (
-                file_name,
-                i64::from(token.get_src_line()),
-                i64::from(token.get_src_col()),
-                source_line,
-              )
-            }
-          },
-        }
-      }
-    };
-  let source_line = source_line
-    .or_else(|| getter.get_source_line(&file_name, line_number as usize));
-  (file_name, line_number + 1, column_number + 1, source_line)
-}
-
-fn get_mappings<'a, G: SourceMapGetter>(
-  file_name: &str,
-  mappings_map: &'a mut CachedMaps,
-  getter: G,
-) -> &'a Option<SourceMap> {
-  mappings_map
-    .entry(file_name.to_string())
-    .or_insert_with(|| parse_map_string(file_name, getter))
-}
-
-// TODO(kitsonk) parsed source maps should probably be cached in state in
-// the module meta data.
-fn parse_map_string<G: SourceMapGetter>(
-  file_name: &str,
-  getter: G,
-) -> Option<SourceMap> {
-  getter
-    .get_source_map(file_name)
-    .and_then(|raw_source_map| SourceMap::from_slice(&raw_source_map).ok())
-}
-
-#[cfg(test)]
-mod tests {
-  use super::*;
-
-  #[derive(Clone)]
-  struct MockSourceMapGetter {}
-
-  impl SourceMapGetter for MockSourceMapGetter {
-    fn get_source_map(&self, file_name: &str) -> Option<Vec<u8>> {
-      let s = match file_name {
-        "foo_bar.ts" => {
-          r#"{"sources": ["foo_bar.ts"], "mappings":";;;IAIA,OAAO,CAAC,GAAG,CAAC,qBAAqB,EAAE,EAAE,CAAC,OAAO,CAAC,CAAC;IAC/C,OAAO,CAAC,GAAG,CAAC,eAAe,EAAE,IAAI,CAAC,QAAQ,CAAC,IAAI,CAAC,CAAC;IACjD,OAAO,CAAC,GAAG,CAAC,WAAW,EAAE,IAAI,CAAC,QAAQ,CAAC,EAAE,CAAC,CAAC;IAE3C,OAAO,CAAC,GAAG,CAAC,GAAG,CAAC,CAAC"}"#
-        }
-        "bar_baz.ts" => {
-          r#"{"sources": ["bar_baz.ts"], "mappings":";;;IAEA,CAAC,KAAK,IAAI,EAAE;QACV,MAAM,GAAG,GAAG,sDAAa,OAAO,2BAAC,CAAC;QAClC,OAAO,CAAC,GAAG,CAAC,GAAG,CAAC,CAAC;IACnB,CAAC,CAAC,EAAE,CAAC;IAEQ,QAAA,GAAG,GAAG,KAAK,CAAC;IAEzB,OAAO,CAAC,GAAG,CAAC,GAAG,CAAC,CAAC"}"#
-        }
-        _ => return None,
-      };
-      Some(s.as_bytes().to_owned())
-    }
-
-    fn get_source_line(
-      &self,
-      file_name: &str,
-      line_number: usize,
-    ) -> Option<String> {
-      let s = match file_name {
-        "foo_bar.ts" => vec![
-          "console.log('foo');",
-          "console.log('foo');",
-          "console.log('foo');",
-          "console.log('foo');",
-          "console.log('foo');",
-        ],
-        _ => return None,
-      };
-      if s.len() > line_number {
-        Some(s[line_number].to_string())
-      } else {
-        None
-      }
-    }
-  }
-
-  #[test]
-  fn apply_source_map_line() {
-    let e = JsError {
-      name: Some("TypeError".to_string()),
-      message: Some("baz".to_string()),
-      exception_message: "TypeError: baz".to_string(),
-      cause: None,
-      source_line: Some("foo".to_string()),
-      script_resource_name: Some("foo_bar.ts".to_string()),
-      line_number: Some(4),
-      start_column: Some(16),
-      end_column: None,
-      frames: vec![],
-      stack: None,
-    };
-    let getter = MockSourceMapGetter {};
-    let actual = apply_source_map(&e, getter);
-    assert_eq!(actual.source_line, Some("console.log('foo');".to_string()));
-  }
-}