#1 - Support snake case parameters like :user-id

Author: rbygrave

src/main/java/io/dinject/javlin/generator/Constants.java

@@ -2,11 +2,13 @@
 
 class Constants {
 
+  static final String IO_JAVALIN_CONTEXT = "io.javalin.Context";
+
   static final String SINGLETON = "javax.inject.Singleton";
   static final String GENERATED = "javax.annotation.Generated";
   static final String API_BUILDER = "io.javalin.apibuilder.ApiBuilder";
 
-  static final String AT_GENERATED = "@Generated(\"io.dinject.web.javlin\")";
+  static final String AT_GENERATED = "@Generated(\"io.dinject.javlin.generator\")";
 
   static final String IMPORT_PATH_TYPE_CONVERT = "import static io.dinject.controller.PathTypeConversion.*;";
 

src/main/java/io/dinject/javlin/generator/MethodParam.java

@@ -5,25 +5,26 @@
 
 class MethodParam {
 
-  private static final String IO_JAVALIN_CONTEXT = "io.javalin.Context";
   private final String rawType;
   private final TypeHandler typeHandler;
   private final String name;
+  private final String snakeName;
 
 
   MethodParam(VariableElement param) {
     this.name = param.getSimpleName().toString();
+    this.snakeName = Util.snakeCase(name);
     this.rawType = param.asType().toString();
     this.typeHandler = TypeMap.get(rawType);
   }
 
-  private boolean isJavlinContext() {
-    return IO_JAVALIN_CONTEXT.equals(rawType);
+  private boolean isJavalinContext() {
+    return Constants.IO_JAVALIN_CONTEXT.equals(rawType);
   }
 
   void buildCtxGet(Append writer, Set<String> pathParams) {
 
-    if (isJavlinContext()) {
+    if (isJavalinContext()) {
       // no conversion for this parameter
       return;
     }
@@ -39,16 +40,14 @@ void buildCtxGet(Append writer, Set<String> pathParams) {
 
     // path parameters are expected to be not nullable
     // ... with query parameters nullable
-    boolean isPathParam = pathParams.contains(name);
-
-    String asMethod = (typeHandler == null) ? null : (isPathParam) ? typeHandler.asMethod() : typeHandler.toMethod();
+    String pathParameter = derivePathParam(pathParams);
+    String asMethod = (typeHandler == null) ? null : (pathParameter != null) ? typeHandler.asMethod() : typeHandler.toMethod();
 
     if (asMethod != null) {
       writer.append(asMethod);
     }
-    if (isPathParam) {
-      writer.append("ctx.pathParam(\"%s\")", name);
-
+    if (pathParameter != null) {
+      writer.append("ctx.pathParam(\"%s\")", pathParameter);
     } else {
       if (typeHandler == null) {
         // assuming this is a body (POST, PATCH)
@@ -64,6 +63,16 @@ void buildCtxGet(Append writer, Set<String> pathParams) {
     writer.append(";").eol();
   }
 
+  private String derivePathParam(Set<String> pathParams) {
+    if (pathParams.contains(name)) {
+      return name;
+    }
+    if (pathParams.contains(snakeName)){
+      return snakeName;
+    }
+    return null;
+  }
+
   void addImports(BeanReader bean) {
     if (typeHandler != null) {
       String importType = typeHandler.getImportType();
@@ -76,7 +85,7 @@ void addImports(BeanReader bean) {
   }
 
   void buildParamName(Append writer) {
-    if (isJavlinContext()) {
+    if (isJavalinContext()) {
       writer.append("ctx");
     } else {
       writer.append(name);

src/main/java/io/dinject/javlin/generator/Util.java

@@ -43,4 +43,23 @@ static String shortName(String fullType) {
       return fullType.substring(p + 1);
     }
   }
+
+  static String snakeCase(String name) {
+
+    StringBuilder sb = new StringBuilder(name.length() + 5);
+
+    int len = name.length();
+    for (int i = 0; i < len; i++) {
+      char ch = name.charAt(i);
+      if (Character.isUpperCase(ch)) {
+        if (i > 0) {
+          sb.append("-");
+        }
+        sb.append(Character.toLowerCase(ch));
+      } else {
+        sb.append(ch);
+      }
+    }
+    return sb.toString();
+  }
 }

src/test/java/io/dinject/javlin/generator/UtilTest.java

@@ -36,4 +36,16 @@ public void pathParams() {
     assertThat(Util.pathParams("/:id/odd:foo")).contains("id");
 
   }
+
+  @Test
+  public void snakeCase() {
+
+    assertThat(Util.snakeCase("lower")).isEqualTo("lower");
+    assertThat(Util.snakeCase("fooId")).isEqualTo("foo-id");
+    assertThat(Util.snakeCase("_fooId")).isEqualTo("_foo-id");
+    assertThat(Util.snakeCase("fooBarBazUuid")).isEqualTo("foo-bar-baz-uuid");
+    assertThat(Util.snakeCase("aDTo")).isEqualTo("a-d-to");
+    assertThat(Util.snakeCase("DTo")).isEqualTo("d-to");
+    assertThat(Util.snakeCase("_DTo")).isEqualTo("_-d-to");
+  }
 }