LibJS: Implement ImportCall and HostImportModuleDynamically

This allows us to load modules from scripts.
This can be dangerous as it can load arbitrary files. Because of that it
fails and throws by default. Currently, only js and JavaScriptTestRunner
enable the default hook.

This also adds tests to test-js which test module code. Because we
form a spec perspective can't "enter" a module this is the easiest way
to run tests without having to modify test-js to have special cases for
modules.
To specify modules in test-js we use the extension '.mjs' this is to
ensure the files are not executed. We do still want to lint these files
so the prettier scripts have changed to look for '.mjs' files as well.

1 files changed, 3 insertions, 3 deletions

diff --git a/Meta/lint-prettier.sh b/Meta/lint-prettier.sh
index 7a6701e8ee..00f0f70b4e 100755
--- a/Meta/lint-prettier.sh
+++ b/Meta/lint-prettier.sh
@@ -10,12 +10,12 @@ if [ "$#" -eq "0" ]; then
         git ls-files \
             --exclude-from .prettierignore \
             -- \
-            '*.js'
+            '*.js' '*.mjs'
     )
 else
     files=()
     for file in "$@"; do
-        if [[ "${file}" == *".js" ]]; then
+        if [[ "${file}" == *".js" ]] || [[ "${file}" == *".mjs" ]]; then
             files+=("${file}")
         fi
     done
@@ -34,5 +34,5 @@ if (( ${#files[@]} )); then
 
     prettier --check "${files[@]}"
 else
-    echo "No .js files to check."
+    echo "No .js or .mjs files to check."
 fi