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.

4 files changed, 14 insertions, 3 deletions

diff --git a/tests/testdata/import_attributes/json_with_shebang.ts b/tests/testdata/import_attributes/json_with_shebang.ts
index 0a785210f..9524026bc 100644
--- a/tests/testdata/import_attributes/json_with_shebang.ts
+++ b/tests/testdata/import_attributes/json_with_shebang.ts
@@ -1,4 +1,3 @@
-// deno-lint-ignore no-import-assertions
-import json from "./json_with_shebang.json" assert { type: "json" };
+import json from "./json_with_shebang.json" with { type: "json" };
 
 console.log(json);
diff --git a/tests/testdata/import_attributes/static_export.out b/tests/testdata/import_attributes/static_export.out
index 41af79d7c..d7e19c80f 100644
--- a/tests/testdata/import_attributes/static_export.out
+++ b/tests/testdata/import_attributes/static_export.out
@@ -1 +1,7 @@
+⚠️  Import assertions are deprecated. Use `with` keyword, instead of 'assert' keyword.
+
+export { default } from "./data.json" assert { type: "json" };
+
+  at file:///[WILDLINE]
+
 { a: "b", c: { d: 10 } }
diff --git a/tests/testdata/import_attributes/static_import.out b/tests/testdata/import_attributes/static_import.out
index e57dffa99..85c75d3eb 100644
--- a/tests/testdata/import_attributes/static_import.out
+++ b/tests/testdata/import_attributes/static_import.out
@@ -1,2 +1,8 @@
+⚠️  Import assertions are deprecated. Use `with` keyword, instead of 'assert' keyword.
+
+import data2 from "./data.json" assert { type: "json" };
+
+  at file:///[WILDLINE]
+
 { a: "b", c: { d: 10 } }
 { a: "b", c: { d: 10 } }
diff --git a/tests/testdata/run/config_json_import.ts b/tests/testdata/run/config_json_import.ts
index 9cf1cceaa..7141f1495 100644
--- a/tests/testdata/run/config_json_import.ts
+++ b/tests/testdata/run/config_json_import.ts
@@ -1,2 +1,2 @@
-import config from "../jsx/deno-jsx.json" assert { type: "json" };
+import config from "../jsx/deno-jsx.json" with { type: "json" };
 console.log(config);