fix(cli): module graph handles redirects properly (#8159)

Fixes #8154

5 files changed, 43 insertions, 6 deletions

diff --git a/cli/module_graph2.rs b/cli/module_graph2.rs
index 6c25ca8f2..df2e5fc61 100644
--- a/cli/module_graph2.rs
+++ b/cli/module_graph2.rs
@@ -763,7 +763,14 @@ impl Graph2 {
     let root_names: Vec<(ModuleSpecifier, MediaType)> = self
       .roots
       .iter()
-      .map(|ms| (ms.clone(), self.get_media_type(ms).unwrap()))
+      .map(|ms| {
+        (
+          // root modules can be redirects, so before we pass it to tsc we need
+          // to resolve the redirect
+          self.resolve_specifier(ms).clone(),
+          self.get_media_type(ms).unwrap(),
+        )
+      })
       .collect();
     let maybe_tsbuildinfo = self.maybe_tsbuildinfo.clone();
     let hash_data =
@@ -793,7 +800,9 @@ impl Graph2 {
       for emit in &response.emitted_files {
         if let Some(specifiers) = &emit.maybe_specifiers {
           assert!(specifiers.len() == 1, "Unexpected specifier length");
-          let specifier = specifiers[0].clone();
+          // The specifier emitted might not be the redirected specifier, and
+          // therefore we need to ensure it is the correct one.
+          let specifier = graph.resolve_specifier(&specifiers[0]);
           // Sometimes if tsc sees a CommonJS file it will _helpfully_ output it
           // to ESM, which we don't really want unless someone has enabled the
           // check_js option.
@@ -805,10 +814,10 @@ impl Graph2 {
           }
           match emit.media_type {
             MediaType::JavaScript => {
-              codes.insert(specifier, emit.data.clone());
+              codes.insert(specifier.clone(), emit.data.clone());
             }
             MediaType::SourceMap => {
-              maps.insert(specifier, emit.data.clone());
+              maps.insert(specifier.clone(), emit.data.clone());
             }
             _ => unreachable!(),
           }
@@ -1139,9 +1148,11 @@ impl Graph2 {
     // instead.
     let result = if prefer_types && dep_module.maybe_types.is_some() {
       let (_, types) = dep_module.maybe_types.clone().unwrap();
-      types
+      // It is possible that `types` points to a redirected specifier, so we
+      // need to ensure it resolves to the final specifier in the graph.
+      self.resolve_specifier(&types).clone()
     } else {
-      resolved_specifier
+      dep_module.specifier.clone()
     };
 
     Ok(result)
diff --git a/cli/tests/integration_tests.rs b/cli/tests/integration_tests.rs
index cfc946a36..da0a311bb 100644
--- a/cli/tests/integration_tests.rs
+++ b/cli/tests/integration_tests.rs
@@ -2859,6 +2859,12 @@ itest!(proto_exploit {
   output: "proto_exploit.js.out",
 });
 
+itest!(redirect_cache {
+  http_server: true,
+  args: "cache --reload http://localhost:4548/cli/tests/subdir/redirects/a.ts",
+  output: "redirect_cache.out",
+});
+
 itest!(deno_test_coverage {
   args: "test --coverage --unstable test_coverage.ts",
   output: "test_coverage.out",
diff --git a/cli/tests/redirect_cache.out b/cli/tests/redirect_cache.out
new file mode 100644
index 000000000..ad26d0108
--- /dev/null
+++ b/cli/tests/redirect_cache.out
@@ -0,0 +1,6 @@
+Download http://localhost:4548/cli/tests/subdir/redirects/a.ts
+Download http://localhost:4546/cli/tests/subdir/redirects/a.ts
+Download http://localhost:4545/cli/tests/subdir/redirects/a.ts
+Download http://localhost:4545/cli/tests/subdir/redirects/b.ts
+Download http://localhost:4545/cli/tests/subdir/redirects/a.ts
+Check http://localhost:4548/cli/tests/subdir/redirects/a.ts
diff --git a/cli/tests/subdir/redirects/a.ts b/cli/tests/subdir/redirects/a.ts
new file mode 100644
index 000000000..071ee4728
--- /dev/null
+++ b/cli/tests/subdir/redirects/a.ts
@@ -0,0 +1,9 @@
+import { createA } from "./b.ts";
+
+export class A {
+  private _a = "a";
+}
+
+export function start(): A {
+  return createA();
+}
diff --git a/cli/tests/subdir/redirects/b.ts b/cli/tests/subdir/redirects/b.ts
new file mode 100644
index 000000000..cdb71eaae
--- /dev/null
+++ b/cli/tests/subdir/redirects/b.ts
@@ -0,0 +1,5 @@
+import { A } from "./a.ts";
+
+export function createA(): A {
+  return new A();
+}