fix: warn about import assertions when using typescript (#25135)

1. On emit, checks for the prescence of import assertions.
1. Warns and doesn't store the parsed source in the emit cache in this
case.

6 files changed, 45 insertions, 0 deletions

diff --git a/tests/specs/run/ts_import_assertions/__test__.jsonc b/tests/specs/run/ts_import_assertions/__test__.jsonc
new file mode 100644
index 000000000..dc5576bd1
--- /dev/null
+++ b/tests/specs/run/ts_import_assertions/__test__.jsonc
@@ -0,0 +1,18 @@
+{
+  "tests": {
+    "assertion": {
+      "steps": [{
+        "args": "run assertion.ts",
+        "output": "assertion.out"
+      }, {
+        // should output the same because the emit won't be cached
+        "args": "run assertion.ts",
+        "output": "assertion.out"
+      }]
+    },
+    "with": {
+      "args": "run with.ts",
+      "output": "with.out"
+    }
+  }
+}
diff --git a/tests/specs/run/ts_import_assertions/assertion.out b/tests/specs/run/ts_import_assertions/assertion.out
new file mode 100644
index 000000000..3cc900d64
--- /dev/null
+++ b/tests/specs/run/ts_import_assertions/assertion.out
@@ -0,0 +1,14 @@
+⚠️  Import assertions are deprecated. Use `with` keyword, instead of 'assert' keyword.
+
+import test from "./data.json" assert { type: "json" };
+
+  at file:///[WILDLINE]/assertion.ts:1:1
+
+{ prop: "data" }
+⚠️  Import assertions are deprecated. Use `with` keyword, instead of 'assert' keyword.
+
+console.log((await import("./data.json", {
+
+  at file:///[WILDLINE]/assertion.ts:5:13
+
+{ prop: "data" }
diff --git a/tests/specs/run/ts_import_assertions/assertion.ts b/tests/specs/run/ts_import_assertions/assertion.ts
new file mode 100644
index 000000000..cb653ffc7
--- /dev/null
+++ b/tests/specs/run/ts_import_assertions/assertion.ts
@@ -0,0 +1,5 @@
+import test from "./data.json" assert { type: "json" };
+console.log(test);
+console.log(
+  (await import("./data.json", { assert: { type: "json" } })).default,
+);
diff --git a/tests/specs/run/ts_import_assertions/data.json b/tests/specs/run/ts_import_assertions/data.json
new file mode 100644
index 000000000..e5b07266c
--- /dev/null
+++ b/tests/specs/run/ts_import_assertions/data.json
@@ -0,0 +1,3 @@
+{
+  "prop": "data"
+}
diff --git a/tests/specs/run/ts_import_assertions/with.out b/tests/specs/run/ts_import_assertions/with.out
new file mode 100644
index 000000000..6141f8c07
--- /dev/null
+++ b/tests/specs/run/ts_import_assertions/with.out
@@ -0,0 +1,2 @@
+{ prop: "data" }
+{ prop: "data" }
diff --git a/tests/specs/run/ts_import_assertions/with.ts b/tests/specs/run/ts_import_assertions/with.ts
new file mode 100644
index 000000000..58b7fb03d
--- /dev/null
+++ b/tests/specs/run/ts_import_assertions/with.ts
@@ -0,0 +1,3 @@
+import test from "./data.json" with { type: "json" };
+console.log(test);
+console.log((await import("./data.json", { with: { type: "json" } })).default);