Review fixes.

Author: tomas-langer

service/inject/README.md

@@ -379,7 +379,7 @@ The generated main class will contain full, reflection less configuration of the
 
 The Main class can also be customized; to do this:
 1. Create a custom class (let's call it `CustomMain` as an example)
-2. The class must extends the injection main class (`public abstract class CustomMain extends InjectionMain`)
+2. The class must extend the injection main class (`public abstract class CustomMain extends InjectionMain`)
 3. The class must be annotated with `@Injection.Main`, so it is discovered by annotation processor
 4. Implement any desired methods; the generated class will only implement `serviceDescriptors(InjectConfig.Builder configBuilder)` (always), and `discoverServices()` (if created from the Maven plugin)
 

service/inject/inject/src/main/java/io/helidon/service/inject/InjectStartupProvider.java

@@ -60,6 +60,7 @@ public void start(String[] arguments) {
 
     @Override
     protected void serviceDescriptors(InjectConfig.Builder configBuilder) {
+        // service descriptors are discovered when startup provider is used - see below discoverServices() method
     }
 
     @Override

service/inject/maven-plugin/src/main/java/io/helidon/service/inject/maven/plugin/BindingGenerator.java

@@ -291,9 +291,14 @@ private InjectionPlan injectionPlan(WrappedServices services,
         Lookup dependencyTo = Lookup.create(dependency);
         Set<Qualifier> qualifiers = dependencyTo.qualifiers();
         if (self.contracts().containsAll(dependencyTo.contracts()) && self.qualifiers().equals(qualifiers)) {
-            // criteria must have a single contract for each injection point
-            // if this service implements the contracts actually required, we must look for services with lower weight
-            // but only if we also have the same qualifiers
+            /*
+            lookup must have a single contract for each injection point
+            if this service implements the contracts actually required, we must look for services with lower weight
+            but only if we also have the same qualifiers;
+            this is to ensure that if an injection point in a service injects a contract the service implements itself,
+            we do not end up in an infinite loop, but look for a service with a lower weight to satisfy that injection point
+            this allows us to "chain" a single contract through multiple services
+             */
             dependencyTo = Lookup.builder(dependencyTo)
                     .weight(self.weight())
                     .build();