Support for Hocon inclusion of files without an extensions. Uses default '.conf'. (helidon-io#4168)

Signed-off-by: Santiago Pericasgeertsen <santiago.pericasgeertsen@oracle.com>

Author: spericas

config/hocon/src/main/java/io/helidon/config/hocon/HoconConfigIncluder.java

@@ -16,6 +16,7 @@
 
 package io.helidon.config.hocon;
 
+import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
@@ -36,6 +37,8 @@
 
 class HoconConfigIncluder implements ConfigIncluder {
     private static final System.Logger LOGGER = System.getLogger(HoconConfigIncluder.class.getName());
+    private static final String HOCON_EXTENSION = ".conf";
+
     private ConfigParseOptions parseOptions;
     private Function<String, Optional<InputStream>> relativeResourceFunction;
     private Charset charset;
@@ -52,7 +55,7 @@ public ConfigIncluder withFallback(ConfigIncluder fallback) {
     public ConfigObject include(ConfigIncludeContext context, String what) {
         LOGGER.log(TRACE, String.format("Received request to include resource %s, %s",
                                         what, context.parseOptions().getOriginDescription()));
-        Optional<InputStream> maybeStream = relativeResourceFunction.apply(what);
+        Optional<InputStream> maybeStream = relativeResourceFunction.apply(patchName(what));
         if (maybeStream.isEmpty()) {
             if (Objects.nonNull(context.parseOptions()) && !context.parseOptions().getAllowMissing()) {
                 throw new ConfigParserException(what + " is missing");
@@ -79,4 +82,19 @@ void relativeResourceFunction(Function<String, Optional<InputStream>> relativeRe
         this.relativeResourceFunction = relativeResourceFunction;
     }
 
+    /**
+     * Adds default Hocon extension if not present.
+     *
+     * @param what file name
+     * @return file name with extension
+     */
+    static String patchName(String what) {
+        Optional<String> base = Optional.of(what)
+                .filter(f -> f.contains(File.separator))
+                .map(f -> f.substring(f.lastIndexOf(File.separator) + 1));
+        Optional<String> ext = Optional.of(base.orElse(what))
+                .filter(f -> f.contains("."))
+                .map(f -> f.substring(f.lastIndexOf(".") + 1));
+        return ext.isPresent() ? what : what + HOCON_EXTENSION;
+    }
 }

config/hocon/src/test/java/io/helidon/config/hocon/IncludeTest.java

@@ -73,4 +73,23 @@ void testIncludesWithRequiredIncludeNotPresent() {
         assertThat(cpe.getMessage(), is("bogus.conf is missing"));
     }
 
+    @Test
+    void testClasspathIncludesNoExtension() {
+        Config config = Config.create(ClasspathConfigSource.create("conf/application4.conf"));
+
+        String value = config.get("app.greeting").asString().orElse(null);
+
+        assertThat("app.greeting should be loaded from application.conf", value, notNullValue());
+        assertThat(value, is("Hello"));
+
+        value = config.get("server.host").asString().orElse(null);
+
+        assertThat("server.host should be loaded from included.conf", value, notNullValue());
+        assertThat(value, is("localhost"));
+
+        value = config.get("server.port").asString().orElse(null);
+
+        assertThat("server.port should be loaded from sub/included.conf", value, notNullValue());
+        assertThat(value, is("8080"));
+    }
 }

config/hocon/src/test/resources/conf/application4.conf

@@ -0,0 +1,22 @@
+#
+# Copyright (c) 2022 Oracle and/or its affiliates.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+include "sub/included"
+include "included"
+
+app {
+  greeting = "Hello"
+}

config/hocon/src/test/resources/conf/sub/included.conf

@@ -16,4 +16,5 @@
 
 server {
   host = "127.0.0.1"
+  port = 8080
 }