adding domain classes

Author: hermanlintvelt

.gitignore

@@ -1,6 +1,6 @@
 *.class
 .gradle
-*/build/
+**/build/
 */bin/
 */.settings/
 .project

aws-sdk-2/expenses-1/README.md

@@ -1,11 +1,9 @@
 # Java AWS Lambda with Serverless.com Tutorial 
 
-## Expense Service Tutorial - Iteration 1 
+## Expense Service Tutorial - Iteration 1
 
-Goal: Define core domain classes
+Goal: Define some domain classes with tests
 
-Steps
-1. Implement `Expense`
-2. Implement `Person`
-3. TODO: other bussiness logic container/"service" class? "Repository" with mocked implementation...
-4. Test!
+Steps:
+1. Create `Expense` and `Person` model classes - with tests
+2. Create a repository interface for creating and retrieving expenses and people - with tests

aws-sdk-2/expenses-1/build.gradle

@@ -1,52 +1,17 @@
-apply plugin: 'java'
+plugins {
+    id 'java'
+}
 
 repositories {
     mavenCentral()
 }
 
-sourceCompatibility = 1.11
-targetCompatibility = 1.11
-
 dependencies {
-//    compile (
-//            'com.amazonaws:aws-lambda-java-core:1.1.0',
-//            'com.amazonaws:aws-lambda-java-log4j:1.0.0',
-//            'com.amazonaws:aws-lambda-java-events:2.2.6',
-//            'com.fasterxml.jackson.core:jackson-core:2.8.5',
-//            'com.fasterxml.jackson.core:jackson-databind:2.8.5',
-//            'com.fasterxml.jackson.core:jackson-annotations:2.8.5'
-//    )
-
-    testImplementation(
-            'org.junit.jupiter:junit-jupiter-api:5.1.0'
-    )
-    testRuntimeOnly(
-            'org.junit.jupiter:junit-jupiter-engine:5.1.0'
-    )
+    testImplementation 'org.assertj:assertj-core:3.22.0'
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.8.2'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.8.2'
 }
 
 test {
-//    environment "STAGE","development"
     useJUnitPlatform()
-}
-
-// Task for building the zip file for upload
-task buildZip(type: Zip) {
-    // Using the Zip API from gradle to build a zip file of all the dependencies
-    //
-    // The path to this zip file can be set in the serverless.yml file for the
-    // package/artifact setting for deployment to the S3 bucket
-    //
-    // Link: https://docs.gradle.org/current/dsl/org.gradle.api.tasks.bundling.Zip.html
-
-    // set the base name of the zip file
-    baseName = "expenses-service"
-    from compileJava
-    from processResources
-    into('lib') {
-        from configurations.runtime
-    }
-}
-
-build.dependsOn buildZip
-
+}

aws-sdk-2/expenses-1/src/main/java/com/example/expenses/model/Expense.java

@@ -0,0 +1,63 @@
+package com.example.expenses.model;
+
+import java.math.BigDecimal;
+import java.time.LocalDate;
+import java.util.Objects;
+import java.util.UUID;
+
+public class Expense {
+    private final UUID id;
+    private final BigDecimal amount;
+    private final LocalDate date;
+    private final Person paidByPerson;
+
+    public Expense(UUID id, BigDecimal amount, LocalDate date, Person paidByPerson) {
+        this.id = id;
+        this.amount = amount;
+        this.date = date;
+        this.paidByPerson = paidByPerson;
+    }
+
+    public Expense(BigDecimal amount, Person paidByPerson) {
+        this(UUID.randomUUID(), amount, LocalDate.now(), paidByPerson);
+    }
+
+    public UUID getId() {
+        return id;
+    }
+
+    public BigDecimal getAmount() {
+        return amount;
+    }
+
+    public LocalDate getDate() {
+        return date;
+    }
+
+    public Person getPaidByPerson() {
+        return paidByPerson;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Expense expense = (Expense) o;
+        return Objects.equals(id, expense.id) && Objects.equals(amount, expense.amount) && Objects.equals(date, expense.date) && Objects.equals(paidByPerson, expense.paidByPerson);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, amount, date, paidByPerson);
+    }
+
+    @Override
+    public String toString() {
+        return "Expense{" +
+                "id=" + id +
+                ", amount=" + amount +
+                ", date=" + date +
+                ", paidByPerson=" + paidByPerson +
+                '}';
+    }
+}

aws-sdk-2/expenses-1/src/main/java/com/example/expenses/model/Person.java

@@ -0,0 +1,28 @@
+package com.example.expenses.model;
+
+public class Person {
+    protected final String email;
+
+    public Person(String email) {
+        this.email = email;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        Person person = (Person) o;
+
+        return email.equals(person.email);
+    }
+
+    @Override
+    public int hashCode() {
+        return email.hashCode();
+    }
+}

aws-sdk-2/expenses-1/src/main/java/com/example/expenses/repository/DataRepository.java

@@ -0,0 +1,64 @@
+package com.example.expenses.repository;
+
+import com.example.expenses.model.Expense;
+import com.example.expenses.model.Person;
+
+import java.util.List;
+import java.util.Optional;
+
+/**
+ * DataRepository:
+ * I define the protocol -- the set of methods -- that other parts of the application can use to
+ * persist instances of the domain model (Persons, Expenses).
+ * <p>
+ * My name, {@code DataRepository}, is intended to indicate the abstract idea that <em>this</em>
+ * is where data lives, without binding to any specific implementation like memory, file or database.
+ * <p>
+ */
+public interface DataRepository {
+
+    /**
+     * Add a new Person instance to the datastore. If the Person passed to this method already exists
+     * in the repository, we'll return that instance and ignore the request.
+     * If you ask for a {@literal null} Person, it will throw a NullPointerException.
+     * @param person A non-null Person instance.
+     * @return The Person instance you added or that already existed in the repository.
+     */
+    Person addPerson(Person person);
+
+    /**
+     * Find a Person instance with the given email address.
+     * @param email Email address of the Person we want to find.
+     * @return An Optional containing the Person if they exist in the repository, empty otherwise.
+     */
+    Optional<Person> findPerson( String email );
+
+    /**
+     * Answer with a List of all Person instances in the repository.
+     * @return A set of Person instances, possible empty, but never {@literal null}.
+     */
+    List<Person> allPersons();
+
+    /**
+     * Add a new Expense instance to the repository.
+     * If this expense's id is null, then it will be filled in with a random UUID.
+     * If this expense's data is null,k then it will be filled in with today's date.
+     * @param expense A non-null Expense instance
+     * @return The Expense instance you added
+     */
+    Expense addExpense(Expense expense);
+
+    /**
+     * Finds all the expenses paid for by specified person.
+     * @param person the non-null Person instance that must match the Expense's paidByPerson field.
+     * @return A set of Expense instances, possible empty, but never {@literal null}. Sorted ascending according to date.
+     */
+    List<Expense> findExpensesPaidBy(Person person);
+
+    /**
+     * Answer with a List of all Expense instances in the repository.
+     * @return A set of Expense instances, possible empty, but never {@literal null}. Sorted ascending according to date.
+     */
+    List<Expense> allExpenses();
+
+}

aws-sdk-2/expenses-1/src/main/java/com/example/expenses/repository/memory/InMemoryRepository.java

@@ -0,0 +1,60 @@
+package com.example.expenses.repository.memory;
+
+import com.example.expenses.model.Expense;
+import com.example.expenses.model.Person;
+import com.example.expenses.repository.DataRepository;
+
+import java.util.*;
+import java.util.stream.Collectors;
+
+public class InMemoryRepository implements DataRepository {
+    private final Set<Person> people = new HashSet<>();
+    private final Set<Expense> expenses = new HashSet<>();
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public List<Person> allPersons() {
+        return people.stream().collect(Collectors.toUnmodifiableList());
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public Optional<Person> findPerson(String email) {
+        return people.stream()
+                .filter(Person -> Person.getEmail().equalsIgnoreCase(email))
+                .findFirst();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public Person addPerson(Person person) {
+        Optional<Person> alreadyExists = findPerson(person.getEmail());
+        if (alreadyExists.isPresent()) {
+            return alreadyExists.get();
+        }
+        people.add(person);
+        return person;
+    }
+
+    @Override
+    public Expense addExpense(Expense expense) {
+        expenses.add(expense);
+        return expense;
+    }
+
+    @Override
+    public List<Expense> findExpensesPaidBy(Person person) {
+        return expenses.stream().filter(expense -> expense.getPaidByPerson().equals(person)).collect(Collectors.toUnmodifiableList());
+    }
+
+    @Override
+    public List<Expense> allExpenses() {
+        return expenses.stream().collect(Collectors.toUnmodifiableList());
+    }
+}

aws-sdk-2/expenses-1/src/test/java/com/example/expenses/model/ExpenseTest.java

@@ -0,0 +1,24 @@
+package com.example.expenses.model;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.math.BigDecimal;
+import java.time.LocalDate;
+import java.util.UUID;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+class ExpenseTest {
+
+    @Test
+    @DisplayName("Two expenses are the same if their fields are the same")
+    void sameExpense() {
+        UUID id = UUID.randomUUID();
+        Person me = new Person("[email protected]");
+        Expense e1 = new Expense(id, BigDecimal.valueOf(100.0), LocalDate.of(2022, 3, 15), me);
+        Expense e2 = new Expense(id, BigDecimal.valueOf(100.0), LocalDate.of(2022, 3, 15), me);
+        assertThat(e1).isEqualTo(e2);
+    }
+
+}

aws-sdk-2/expenses-1/src/test/java/com/example/expenses/model/PersonTest.java

@@ -0,0 +1,18 @@
+package com.example.expenses.model;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+class PersonTest {
+
+    @Test
+    @DisplayName("Two people are the same if their emails are the same")
+    void samePerson() {
+        Person p1 = new Person("[email protected]");
+        Person p2 = new Person("[email protected]");
+        assertThat(p1).isEqualTo(p2);
+    }
+
+}