feat(unstable): fast subset type checking of JSR dependencies (#21873)

2 files changed, 68 insertions, 5 deletions

diff --git a/cli/tsc/diagnostics.rs b/cli/tsc/diagnostics.rs
index b11a8b536..56610106b 100644
--- a/cli/tsc/diagnostics.rs
+++ b/cli/tsc/diagnostics.rs
@@ -1,11 +1,14 @@
 // Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
 
+use deno_ast::ModuleSpecifier;
+use deno_graph::ModuleGraph;
 use deno_runtime::colors;
 
 use deno_core::serde::Deserialize;
 use deno_core::serde::Deserializer;
 use deno_core::serde::Serialize;
 use deno_core::serde::Serializer;
+use deno_core::sourcemap::SourceMap;
 use std::error::Error;
 use std::fmt;
 
@@ -101,7 +104,9 @@ impl DiagnosticMessageChain {
 #[derive(Debug, Deserialize, Serialize, Clone, Eq, PartialEq)]
 #[serde(rename_all = "camelCase")]
 pub struct Position {
+  /// 0-indexed line number
   pub line: u64,
+  /// 0-indexed character number
   pub character: u64,
 }
 
@@ -112,6 +117,13 @@ pub struct Diagnostic {
   pub code: u64,
   pub start: Option<Position>,
   pub end: Option<Position>,
+  /// Position of this diagnostic in the original non-mapped source.
+  ///
+  /// This will exist and be different from the `start` for fast
+  /// checked modules where the TypeScript source will differ
+  /// from the original source.
+  #[serde(skip_serializing)]
+  pub original_source_start: Option<Position>,
   pub message_text: Option<String>,
   #[serde(skip_serializing_if = "Option::is_none")]
   pub message_chain: Option<DiagnosticMessageChain>,
@@ -145,9 +157,10 @@ impl Diagnostic {
   }
 
   fn fmt_frame(&self, f: &mut fmt::Formatter, level: usize) -> fmt::Result {
-    if let (Some(file_name), Some(start)) =
-      (self.file_name.as_ref(), self.start.as_ref())
-    {
+    if let (Some(file_name), Some(start)) = (
+      self.file_name.as_ref(),
+      self.original_source_start.as_ref().or(self.start.as_ref()),
+    ) {
       write!(
         f,
         "\n{:indent$}    at {}:{}:{}",
@@ -273,6 +286,51 @@ impl Diagnostics {
   pub fn is_empty(&self) -> bool {
     self.0.is_empty()
   }
+
+  /// Modifies all the diagnostics to have their display positions
+  /// modified to point at the original source.
+  pub fn apply_fast_check_source_maps(&mut self, graph: &ModuleGraph) {
+    fn visit_diagnostic(d: &mut Diagnostic, graph: &ModuleGraph) {
+      if let Some(specifier) = d
+        .file_name
+        .as_ref()
+        .and_then(|n| ModuleSpecifier::parse(n).ok())
+      {
+        if let Ok(Some(module)) = graph.try_get_prefer_types(&specifier) {
+          if let Some(fast_check_module) =
+            module.esm().and_then(|m| m.fast_check_module())
+          {
+            // todo(dsherret): use a short lived cache to prevent parsing
+            // source maps so often
+            if let Ok(source_map) =
+              SourceMap::from_slice(&fast_check_module.source_map)
+            {
+              if let Some(start) = d.start.as_mut() {
+                let maybe_token = source_map
+                  .lookup_token(start.line as u32, start.character as u32);
+                if let Some(token) = maybe_token {
+                  d.original_source_start = Some(Position {
+                    line: token.get_src_line() as u64,
+                    character: token.get_src_col() as u64,
+                  });
+                }
+              }
+            }
+          }
+        }
+      }
+
+      if let Some(related) = &mut d.related_information {
+        for d in related.iter_mut() {
+          visit_diagnostic(d, graph);
+        }
+      }
+    }
+
+    for d in &mut self.0 {
+      visit_diagnostic(d, graph);
+    }
+  }
 }
 
 impl<'de> Deserialize<'de> for Diagnostics {
diff --git a/cli/tsc/mod.rs b/cli/tsc/mod.rs
index 4e9b6110b..4df841cd3 100644
--- a/cli/tsc/mod.rs
+++ b/cli/tsc/mod.rs
@@ -486,7 +486,11 @@ fn op_load(
       match module {
         Module::Esm(module) => {
           media_type = module.media_type;
-          Some(Cow::Borrowed(&*module.source))
+          let source = module
+            .fast_check_module()
+            .map(|m| &*m.source)
+            .unwrap_or(&*module.source);
+          Some(Cow::Borrowed(source))
         }
         Module::Json(module) => {
           media_type = MediaType::Json;
@@ -586,7 +590,7 @@ fn op_resolve(
     let resolved_dep = graph
       .get(&referrer)
       .and_then(|m| m.esm())
-      .and_then(|m| m.dependencies.get(&specifier))
+      .and_then(|m| m.dependencies_prefer_fast_check().get(&specifier))
       .and_then(|d| d.maybe_type.ok().or_else(|| d.maybe_code.ok()));
 
     let maybe_result = match resolved_dep {
@@ -1182,6 +1186,7 @@ mod tests {
           code: 5023,
           start: None,
           end: None,
+          original_source_start: None,
           message_text: Some(
             "Unknown compiler option \'invalid\'.".to_string()
           ),