WIP

Author: mpkorstanje

docstring/src/main/java/io/cucumber/docstring/DocStringTypeRegistryDocStringConverter.java

@@ -60,12 +60,14 @@ public <T> T convert(DocString docString, Type targetType) {
     private List<String> suggestedContentTypes(List<DocStringType> docStringTypes) {
         return docStringTypes.stream()
                 .map(DocStringType::getContentType)
-                // Can't use the anonymous content type to resolve
-                // the ambiguity.
-                .filter(contentType -> !contentType.isEmpty())
+                .map(DocStringTypeRegistryDocStringConverter::emptyToAnonymous)
                 .sorted()
                 .distinct()
                 .collect(Collectors.toList());
     }
 
+    private static String emptyToAnonymous(String contentType) {
+        return contentType.isEmpty() ? "[anonymous]" : contentType;
+    }
+
 }

docstring/src/test/java/io/cucumber/docstring/DocStringTypeRegistryDocStringConverterTest.java

@@ -10,20 +10,42 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.equalToCompressingWhiteSpace;
+import static org.junit.jupiter.api.Assertions.assertAll;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 class DocStringTypeRegistryDocStringConverterTest {
 
-    private final DocStringTypeRegistry registry = new DocStringTypeRegistry();
-    private final DocStringTypeRegistryDocStringConverter converter = new DocStringTypeRegistryDocStringConverter(
-        registry);
+    static final DocStringType jsonNodeForJson = new DocStringType(
+            JsonNode.class,
+            "json",
+            (String s) -> new ObjectMapper().readTree(s));
+    static final DocStringType stringForText = new DocStringType(
+            String.class,
+            "text",
+            (String s) -> s);
+    static final DocStringType stringForXml = new DocStringType(
+            String.class,
+            "xml",
+            (String s) -> s);
+    static final DocStringType stringForYaml = new DocStringType(
+            String.class,
+            "yml",
+            (String s) -> s);
+    public static final DocStringType jsonNodeForXml = new DocStringType(
+            JsonNode.class,
+            "xml",
+            (String s) -> new ObjectMapper().readTree(s));
+    public static final DocStringType stringForJson = new DocStringType(
+            String.class,
+            "json",
+            (String s) -> s);
+
+    final DocStringTypeRegistry registry = new DocStringTypeRegistry();
+    final DocStringTypeRegistryDocStringConverter converter = new DocStringTypeRegistryDocStringConverter(registry);
 
     @Test
     void throws_when_uses_doc_string_type_but_downcast_conversion() {
-        registry.defineDocStringType(new DocStringType(
-            JsonNode.class,
-            "json",
-            (String s) -> new ObjectMapper().readTree(s)));
+        registry.defineDocStringType(jsonNodeForJson);
 
         DocString docString = DocString.create(
             "{\"hello\":\"world\"}",
@@ -39,10 +61,7 @@ void throws_when_uses_doc_string_type_but_downcast_conversion() {
 
     @Test
     void uses_target_type_when_available() {
-        registry.defineDocStringType(new DocStringType(
-            JsonNode.class,
-            "json",
-            (String s) -> new ObjectMapper().readTree(s)));
+        registry.defineDocStringType(jsonNodeForJson);
 
         DocString docString = DocString.create(
             "{\"hello\":\"world\"}");
@@ -62,10 +81,7 @@ void target_type_to_string_is_predefined() {
 
     @Test
     void default_converter_is_used_if_registered_converter_does_not_match_type() {
-        registry.defineDocStringType(new DocStringType(
-            JsonNode.class,
-            "json",
-            (String s) -> new ObjectMapper().readTree(s)));
+        registry.defineDocStringType(jsonNodeForJson);
 
         DocString docString = DocString.create(
             "hello world", "json");
@@ -76,10 +92,7 @@ void default_converter_is_used_if_registered_converter_does_not_match_type() {
 
     @Test
     void default_converter_never_conflicts_with_registered_converter_for_string() {
-        registry.defineDocStringType(new DocStringType(
-            String.class,
-            "text",
-            (String s) -> s));
+        registry.defineDocStringType(stringForText);
 
         DocString docString = DocString.create("hello world");
 
@@ -89,25 +102,20 @@ void default_converter_never_conflicts_with_registered_converter_for_string() {
 
     @Test
     void throws_if_converter_type_conflicts_with_type() {
-        registry.defineDocStringType(new DocStringType(
-            JsonNode.class,
-            "json",
-            (String s) -> new ObjectMapper().readTree(s)));
-
-        registry.defineDocStringType(new DocStringType(
-            String.class,
-            "text",
-            (String s) -> s));
+        registry.defineDocStringType(jsonNodeForJson);
+        registry.defineDocStringType(stringForText);
 
         DocString docString = DocString.create("hello world", "json");
 
         CucumberDocStringException exception = assertThrows(
             CucumberDocStringException.class,
             () -> converter.convert(docString, String.class));
 
+        // TODO: This exception should explain,
+
         assertThat(exception.getMessage(),
             is("Multiple converters found for type java.lang.String, and the content type 'json' " +
-                    "did not match any of the registered types [text]. Change the content type of the docstring " +
+                    "did not match any of the registered types [[anonymous], text]. Change the content type of the docstring " +
                     "or register a docstring type for 'json'"));
     }
 
@@ -187,15 +195,9 @@ void converts_no_content_type_doc_string_to_registered_matching_convertor() {
 
     @Test
     void throws_when_multiple_convertors_available() {
-        registry.defineDocStringType(new DocStringType(
-            JsonNode.class,
-            "json",
-            (String s) -> new ObjectMapper().readTree(s)));
+        registry.defineDocStringType(jsonNodeForJson);
 
-        registry.defineDocStringType(new DocStringType(
-            JsonNode.class,
-            "xml",
-            (String s) -> new ObjectMapper().readTree(s)));
+        registry.defineDocStringType(jsonNodeForXml);
 
         DocString docString = DocString.create(
             "{\"hello\":\"world\"}");
@@ -211,20 +213,9 @@ void throws_when_multiple_convertors_available() {
 
     @Test
     void different_docstring_content_types_convert_to_matching_doc_string_types() {
-        registry.defineDocStringType(new DocStringType(
-            String.class,
-            "json",
-            (String s) -> s));
-
-        registry.defineDocStringType(new DocStringType(
-            String.class,
-            "xml",
-            (String s) -> s));
-
-        registry.defineDocStringType(new DocStringType(
-            String.class,
-            "yml",
-            (String s) -> s));
+        registry.defineDocStringType(stringForJson);
+        registry.defineDocStringType(stringForXml);
+        registry.defineDocStringType(stringForYaml);
 
         DocString docStringJson = DocString.create(
             "{\"content\":\"hello world\"}", "json");
@@ -237,9 +228,11 @@ void different_docstring_content_types_convert_to_matching_doc_string_types() {
         String convertXml = converter.convert(docStringXml, String.class);
         String convertYml = converter.convert(docStringYml, String.class);
 
-        assertThat(docStringJson.getContent(), equalTo(convertJson));
-        assertThat(docStringXml.getContent(), equalTo(convertXml));
-        assertThat(docStringYml.getContent(), equalTo(convertYml));
+        assertAll(
+                () -> assertThat(docStringJson.getContent(), equalTo(convertJson)),
+                () -> assertThat(docStringXml.getContent(), equalTo(convertXml)),
+                () -> assertThat(docStringYml.getContent(), equalTo(convertYml))
+        );
     }
 
     @Test

java/src/main/java/io/cucumber/java/DocStringType.java

@@ -10,14 +10,22 @@
 /**
  * Register doc string type.
  * <p>
- * The name of the method is used as the content type of the
- * {@link io.cucumber.docstring.DocStringType}.
- * <p>
  * The method must have this signature:
  * <ul>
  * <li>{@code String -> Author}</li>
  * </ul>
  * NOTE: {@code Author} is an example of the type of the parameter type.
+ * <p>
+ * TODO: Explain how docstring types are selected.
+ * TODO: Explain anonymous docstring type
+ * TODO: Explain existence of default converter
+ * First by content type and target type.
+ * Then by target type.
+ *
+ *
+ * NOTE: When not provided the name of the method is used as the content type of the {@link io.cucumber.docstring.DocStringType}.
+ *
+ *
  *
  * @see io.cucumber.docstring.DocStringType
  */