Check if the parsed ruby is unknown in parse_ruby (closes #450)

ChangeLog.md

@@ -6,6 +6,8 @@
 * Fixed an implicit string splitting bug when passing in compiler env variables
   via the additional configuration options
   (ex: `ruby-install ruby -- CFLAGS="-O3 ..."`).
+* Catch unknown ruby implementation names early before attempting to download
+  version information for them.
 
 #### truffleruby
 

share/ruby-install/ruby-install.sh

@@ -97,6 +97,11 @@ function parse_ruby()
 			ruby="$string"
 			;;
 	esac
+
+	if [[ ! "${rubies[*]}" == *"$ruby"* ]]; then
+		echo "ruby-install: unknown ruby: $ruby" >&2
+		return 1
+	fi
 }
 
 #
@@ -267,11 +272,6 @@ function list_rubies()
 #
 function init()
 {
-	if [[ ! "${rubies[*]}" == *"$ruby"* ]]; then
-		error "Unknown ruby: $ruby"
-		return 1
-	fi
-
 	local fully_qualified_version="$(lookup_ruby_version "$ruby" "$ruby_version")"
 
 	if [[ -n "$fully_qualified_version" ]]; then

test/ruby-install-tests/parse_ruby_test.sh

@@ -56,4 +56,14 @@ function test_parse_ruby_when_the_ruby_name_contains_multiple_dashes()
 	                                               "$ruby_version"
 }
 
+function test_parse_ruby_with_an_unknown_ruby()
+{
+	local unknown_ruby="foo"
+	local output="$(parse_ruby "$unknown_ruby" 2>&1)"
+
+	assertEquals "did not print an error for an unknwon ruby" \
+		     "ruby-install: unknown ruby: $unknown_ruby" \
+		     "$output"
+}
+
 SHUNIT_PARENT=$0 . $SHUNIT2