fix(imports): fix panic on unsupported scheme (denoland#5131)

cli/file_fetcher.rs

@@ -93,7 +93,7 @@ impl SourceFileFetcher {
     Ok(file_fetcher)
   }
 
-  fn check_if_supported_scheme(url: &Url) -> Result<(), ErrBox> {
+  pub fn check_if_supported_scheme(url: &Url) -> Result<(), ErrBox> {
     if !SUPPORTED_URL_SCHEMES.contains(&url.scheme()) {
       return Err(
         OpError::other(

cli/state.rs

@@ -1,5 +1,6 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 use crate::compilers::TargetLib;
+use crate::file_fetcher::SourceFileFetcher;
 use crate::global_state::GlobalState;
 use crate::global_timer::GlobalTimer;
 use crate::import_map::ImportMap;
@@ -474,6 +475,10 @@ impl State {
     module_specifier: &ModuleSpecifier,
   ) -> Result<(), OpError> {
     let u = module_specifier.as_url();
+    // TODO(bartlomieju): temporary fix to prevent hitting `unreachable`
+    // statement that is actually reachable...
+    SourceFileFetcher::check_if_supported_scheme(u)?;
+
     match u.scheme() {
       "http" | "https" => {
         self.check_net_url(u)?;

cli/tests/integration_tests.rs

@@ -1583,6 +1583,13 @@ itest!(run_v8_help {
   output: "v8_help.out",
 });
 
+itest!(unsupported_dynamic_import_scheme {
+  args: "eval import('xxx:')",
+  output: "unsupported_dynamic_import_scheme.out",
+  check_stderr: true,
+  exit_code: 1,
+});
+
 itest!(wasm {
   args: "run wasm.ts",
   output: "wasm.ts.out",

cli/tests/unsupported_dynamic_import_scheme.out

@@ -0,0 +1,5 @@
+error: Uncaught TypeError: Unsupported scheme "xxx" for module "xxx:". Supported schemes: [
+    "http",
+    "https",
+    "file",
+]