Fix #50: error when modules loaded twice

Author: lptr

spaghetti-core/src/main/groovy/com/prezi/spaghetti/config/ModuleConfigurationParser.groovy

@@ -1,6 +1,7 @@
 package com.prezi.spaghetti.config
 
 import com.prezi.spaghetti.ast.ModuleNode
+import com.prezi.spaghetti.ast.parser.AstParserException
 import com.prezi.spaghetti.ast.parser.MissingTypeResolver
 import com.prezi.spaghetti.ast.parser.ModuleParser
 import com.prezi.spaghetti.ast.parser.ModuleTypeResolver
@@ -15,19 +16,27 @@ class ModuleConfigurationParser {
 			Collection<ModuleDefinitionSource> localModuleSources,
 			Collection<ModuleDefinitionSource> dependentModuleSources,
 			Collection<ModuleDefinitionSource> transitiveModuleSources) {
+		Set<String> parsedModules = []
 		def configNode = new DefaultModuleConfiguration()
-		def transitiveResolver = resolveModules(MissingTypeResolver.INSTANCE, transitiveModuleSources, configNode.transitiveDependentModules)
-		def directResolver = resolveModules(transitiveResolver, dependentModuleSources, configNode.directDependentModules)
-		resolveModules(directResolver, localModuleSources, configNode.localModules)
+		def transitiveResolver = parseModules(MissingTypeResolver.INSTANCE, transitiveModuleSources, configNode.transitiveDependentModules, parsedModules)
+		def directResolver = parseModules(transitiveResolver, dependentModuleSources, configNode.directDependentModules, parsedModules)
+		parseModules(directResolver, localModuleSources, configNode.localModules, parsedModules)
 		return configNode
 	}
 
-	static TypeResolver resolveModules(TypeResolver parentResolver, Collection<ModuleDefinitionSource> sources, Set<ModuleNode> moduleNodes) {
+	static TypeResolver parseModules(TypeResolver parentResolver, Collection<ModuleDefinitionSource> sources, Set<ModuleNode> moduleNodes, Set<String> allModuleNames) {
 		List<ModuleParser> parsers = sources.collect { ModuleParser.create(it) }
 		def resolver = parsers.inject(parentResolver) {
 			TypeResolver resolver, parser -> new ModuleTypeResolver(resolver, parser.module)
 		}
-		moduleNodes.addAll parsers*.parse(resolver)
+		parsers.each { parser ->
+			def module = parser.parse(resolver)
+			if (allModuleNames.contains(module.name)) {
+				throw new AstParserException(module.source, ": module loaded multiple times: ${module.name}")
+			}
+			allModuleNames.add(module.name)
+			moduleNodes.add module
+		}
 		return resolver
 	}
 }

spaghetti-core/src/test/groovy/com/prezi/spaghetti/config/ModuleConfigurationParserTest.groovy

@@ -0,0 +1,23 @@
+package com.prezi.spaghetti.config
+
+import com.prezi.spaghetti.ast.parser.AstParserException
+import com.prezi.spaghetti.definition.ModuleDefinitionSource
+import spock.lang.Specification
+
+/**
+ * Created by lptr on 01/06/14.
+ */
+class ModuleConfigurationParserTest extends Specification {
+	def "Loaded multiple times"() {
+		when:
+		ModuleConfigurationParser.parse(
+				[new ModuleDefinitionSource("C:\\test1.module", "module com.example.test")],
+				[],
+				[new ModuleDefinitionSource("C:\\test2.module", "module com.example.test")]
+		)
+
+		then:
+		def ex = thrown AstParserException
+		ex.message == "Parse error in C:\\test1.module: module loaded multiple times: com.example.test"
+	}
+}