Detect missing fixtures submodule (#2105)

* Detect missing Prism fixtures submodule

* Remove unnecessary extra check

Author: andyw8

bin/test

@@ -1,13 +1,5 @@
 #!/usr/bin/env bash
 
-PRISM_FIXTURES_DIR=test/fixtures/prism/test/prism/fixtures
-
-if [ ! -d "$PRISM_FIXTURES_DIR" ]; then
-    echo "$PRISM_FIXTURES_DIR does not exist."
-    echo "Please run 'git submodule update --init' to pull submodule fixtures."
-    exit 1
-fi
-
 if [[ 2 -eq $# ]]; then
   bundle exec rake TEST="$1" TESTOPTS="-n='/$2/'"
 elif [[ 1 -eq $# ]]; then

lib/ruby_indexer/test/index_test.rb

@@ -299,6 +299,10 @@ def baz; end
     end
 
     def test_indexing_prism_fixtures_succeeds
+      unless Dir.exist?("test/fixtures/prism/test/prism/fixtures")
+        raise "Prism fixtures not found. Run `git submodule update --init` to fetch them."
+      end
+
       fixtures = Dir.glob("test/fixtures/prism/test/prism/fixtures/**/*.txt")
 
       fixtures.each do |fixture|