Adding analyzer feedback for cars-assemble concept exercise (#2756)

* Adding analyzer feedback for cars-assemble concept exercise

* Update exercises/concept/cars-assemble/.meta/design.md

Co-authored-by: Sander Ploegsma <[email protected]>

* Update exercises/concept/cars-assemble/.meta/design.md

Co-authored-by: Sander Ploegsma <[email protected]>

* Update exercises/concept/cars-assemble/.meta/design.md

Co-authored-by: Sander Ploegsma <[email protected]>

---------

Co-authored-by: Sander Ploegsma <[email protected]>

Author: manumafe98

exercises/concept/cars-assemble/.meta/design.md

@@ -25,3 +25,17 @@ This exercise's prerequisites Concepts are:
 
 - `basics`: know how to define methods.
 - `booleans`: know how to use boolean operators.
+
+## Analyzer
+
+This exercise could benefit from the following rules in the [analyzer]:
+
+- `actionable`: If the student did not reuse the implementation of the `productionRatePerHour` method in the `workingItemsPerMinute` method, instruct them to do so.
+- `informative`: If the solution is repeatedly hard-coding the value `221`, inform the student that they could store this value in a field to make the code easier to maintain.
+- `informative`: If the solution has `if/else-if` statements in the `productionRatePerHour` method, inform the student that creating a helper method to calculate the succes rate might make their code easier to understand.
+- `informative`: If the solution is using `if/else-if` logic that contains return statements, inform the students that the `else` keywords are redundant and that their code can become more clear by omitting them.
+
+If the solution does not receive any of the above feedback, it must be exemplar.
+Leave a `celebratory` comment to celebrate the success!
+
+[analyzer]: https://github.com/exercism/java-analyzer

exercises/concept/cars-assemble/.meta/src/reference/java/CarsAssemble.java

@@ -4,17 +4,13 @@ public class CarsAssemble {
     private final int defaultProductionRate = 221;
 
     public double productionRatePerHour(int speed) {
-        return productionRatePerHourForSpeed(speed) * successRate(speed);
+        return defaultProductionRate * speed * successRate(speed);
     }
 
     public int workingItemsPerMinute(int speed) {
         return (int) (productionRatePerHour(speed) / 60);
     }
 
-    private int productionRatePerHourForSpeed(int speed) {
-        return defaultProductionRate * speed;
-    }
-
     private double successRate(int speed) {
         if (speed == 10) {
             return 0.77;