fix(publish): lazily parse sources (#22301)

Closes #22290

2 files changed, 34 insertions, 0 deletions

diff --git a/cli/cache/mod.rs b/cli/cache/mod.rs
index 7004f11af..fc6421056 100644
--- a/cli/cache/mod.rs
+++ b/cli/cache/mod.rs
@@ -46,6 +46,7 @@ pub use emit::EmitCache;
 pub use incremental::IncrementalCache;
 pub use module_info::ModuleInfoCache;
 pub use node::NodeAnalysisCache;
+pub use parsed_source::LazyGraphSourceParser;
 pub use parsed_source::ParsedSourceCache;
 
 /// Permissions used to save a file in the disk caches.
diff --git a/cli/cache/parsed_source.rs b/cli/cache/parsed_source.rs
index 7bb1a72a7..75170aaf9 100644
--- a/cli/cache/parsed_source.rs
+++ b/cli/cache/parsed_source.rs
@@ -11,6 +11,39 @@ use deno_graph::CapturingModuleParser;
 use deno_graph::ModuleParser;
 use deno_graph::ParseOptions;
 
+/// Lazily parses JS/TS sources from a `deno_graph::ModuleGraph` given
+/// a `ParsedSourceCache`. Note that deno_graph doesn't necessarily cause
+/// files to end up in the `ParsedSourceCache` because it might have all
+/// the information it needs via caching in order to skip parsing.
+#[derive(Clone, Copy)]
+pub struct LazyGraphSourceParser<'a> {
+  cache: &'a ParsedSourceCache,
+  graph: &'a deno_graph::ModuleGraph,
+}
+
+impl<'a> LazyGraphSourceParser<'a> {
+  pub fn new(
+    cache: &'a ParsedSourceCache,
+    graph: &'a deno_graph::ModuleGraph,
+  ) -> Self {
+    Self { cache, graph }
+  }
+
+  pub fn get_or_parse_source(
+    &self,
+    module_specifier: &ModuleSpecifier,
+  ) -> Result<Option<deno_ast::ParsedSource>, deno_ast::Diagnostic> {
+    let Some(deno_graph::Module::Js(module)) = self.graph.get(module_specifier)
+    else {
+      return Ok(None);
+    };
+    self
+      .cache
+      .get_parsed_source_from_js_module(module)
+      .map(Some)
+  }
+}
+
 #[derive(Default)]
 pub struct ParsedSourceCache {
   sources: Mutex<HashMap<ModuleSpecifier, ParsedSource>>,