replace invalid characters in generated method names with underscore (#519)

* replace invalid characters in generated method names with underscore

fixes #518

spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/MethodBuilder.groovy

@@ -61,7 +61,7 @@ class MethodBuilder {
 		return new MethodBuilder(methodName, stubContent, configProperties, contract.ignored || stubContent.ignored)
 	}
 
-	private static String methodName(ContractMetadata contract, File stubsFile, Contract stubContent) {
+	static String methodName(ContractMetadata contract, File stubsFile, Contract stubContent) {
 		if (stubContent.name) {
 			return NamesUtil.camelCase(NamesUtil.convertIllegalPackageChars(stubContent.name))
 		} else if (contract.convertedContract.size() > 1) {
@@ -72,7 +72,7 @@ class MethodBuilder {
 	}
 
 	private static String camelCasedMethodFromFileName(File stubsFile) {
-		return NamesUtil.camelCase(NamesUtil.toLastDot(NamesUtil.afterLast(stubsFile.path, File.separator)))
+		return NamesUtil.camelCase(NamesUtil.convertIllegalMethodNameChars(NamesUtil.toLastDot(NamesUtil.afterLast(stubsFile.path, File.separator))))
 	}
 
 	/**

spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/util/NamesUtil.groovy

@@ -111,4 +111,13 @@ class NamesUtil {
 	static String convertIllegalPackageChars(String packageName) {
 		return packageName.replaceAll('[_\\- .+]', '_')
 	}
+
+	/**
+	 * Converts illegal characters in method names to underscores
+	 */
+	static String convertIllegalMethodNameChars(String methodName) {
+		String result =  methodName.replaceAll('^[^a-zA-Z_$]', '_')
+		result = result.replaceAll('[^a-zA-Z_$0-9]', '_')
+		return result
+	}
 }

spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/builder/MethodBuilderSpec.groovy

@@ -0,0 +1,34 @@
+package org.springframework.cloud.contract.verifier.builder
+
+import org.springframework.cloud.contract.spec.Contract
+import org.springframework.cloud.contract.verifier.file.ContractMetadata
+import spock.lang.Issue
+import spock.lang.Specification
+
+class MethodBuilderSpec extends Specification {
+
+    @Issue('#518')
+    def "should map create valid method name from file name containing illegal chars"() {
+        given:
+            Contract contractDsl = Contract.make {
+                request {
+                    method 'GET'
+                    urlPath '/foo'
+                }
+                response {
+                    status 200
+                    body(foo: "foo")
+                    headers {
+                        contentType(applicationJson())
+                    }
+                }
+            }
+            ContractMetadata metadata = new ContractMetadata(null, false, 0, null, contractDsl)
+        when:
+            File stubFile = new File("5invalid-method:name.groovy")
+            String methodName = MethodBuilder.methodName(metadata, stubFile, contractDsl)
+        then:
+            methodName.equals("_invalid_method_name")
+    }
+
+}

spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/util/NamesUtilSpec.groovy

@@ -104,4 +104,11 @@ class NamesUtilSpec extends Specification {
 		expect:
 			NamesUtil.convertIllegalPackageChars(string) == "a_b_c_1_0_x_d1174dd"
 	}
+
+	def "should convert all illegal method chars to legal ones"() {
+		given:
+			String string = '10a-b c.1.0.x+d1174$dd'
+		expect:
+			NamesUtil.convertIllegalMethodNameChars(string) == '_0a_b_c_1_0_x_d1174$dd'
+	}
 }