Add Method Chaining (ES5 + ES6 + CoffeeScript + TypeScript)

Author: Badacadabra

misc/MethodChaining/CoffeeScript/index.coffee

@@ -0,0 +1,14 @@
+person =
+    setFirstName: (@firstName = "John") -> @
+    setLastName: (@lastName = "Doe") -> @
+    sayHello: -> 
+        if !@firstName or !@lastName
+            throw
+                type: "No data"
+                message: "A person needs a first name and a last name before to say hello."
+        "Hello, #{this.firstName} #{this.lastName}!"
+
+try
+    console.log person.setFirstName("Baptiste").setLastName("Vannesson").sayHello() # Here is the chain!
+catch e
+    console.log #{e.type} - #{e.message}

misc/MethodChaining/ECMAScript/ES5/index.js

@@ -0,0 +1,25 @@
+var person = {
+    setFirstName: function (firstName) {
+        this.firstName = firstName || "John";
+        return this;
+    },
+    setLastName: function (lastName) {
+        this.lastName = lastName || "Doe";
+        return this;
+    },
+    sayHello: function () {
+        if (!this.firstName || !this.lastName) {
+            throw {
+                type: "No data",
+                message: "A person needs a first name and a last name before to say hello."
+            }; 
+        }
+        return "Hello, " + this.firstName + " " + this.lastName + "!"; 
+    }
+};
+
+try {
+    console.log(person.setFirstName("Baptiste").setLastName("Vannesson").sayHello()); // Here is the chain!
+} catch (e) {
+    console.log(e.type + " - " + e.message);
+}

misc/MethodChaining/ECMAScript/ES6/index.js

@@ -0,0 +1,25 @@
+const person = {
+    setFirstName(firstName = "John") {
+        this.firstName = firstName;
+        return this;
+    },
+    setLastName(lastName = "Doe") {
+        this.lastName = lastName;
+        return this;
+    },
+    sayHello() {
+        if (!this.firstName || !this.lastName) {
+            throw {
+                type: "No data",
+                message: "A person needs a first name and a last name before to say hello."
+            }; 
+        }
+        return `Hello, ${this.firstName} ${this.lastName}!`; 
+    }
+};
+
+try {
+    console.log(person.setFirstName("Baptiste").setLastName("Vannesson").sayHello()); // Here is the chain!
+} catch (e) {
+    console.log(e.type + " - " + e.message);
+}

misc/MethodChaining/README.md

@@ -0,0 +1,7 @@
+# Problem
+
+In a program, we may have a lot of function calls on the same object. This often leads to repetition because it is necessary to write the reference again and again.
+
+# Solution
+
+Method Chaining allows us to make multiple calls on the same object without repeating ourselves. This pattern is very easy to use because the only thing to do is to return the current object ("this") in all methods that are supposed to be "chainable".

misc/MethodChaining/TypeScript/index.ts

@@ -0,0 +1,31 @@
+interface Person {
+    setFirstName(firstName: string): Person;
+    setLastName(lastName: string): Person;
+    sayHello(): string | never;
+}
+
+const person: Person = {
+    setFirstName(firstName: string = "John"): Person {
+        this.firstName = firstName;
+        return this;
+    },
+    setLastName(lastName: string = "Doe"): Person {
+        this.lastName = lastName;
+        return this;
+    },
+    sayHello(): string | never {
+        if (!this.firstName || !this.lastName) {
+            throw {
+                type: "No data",
+                message: "A person needs a first name and a last name before to say hello."
+            }; 
+        }
+        return `Hello, ${this.firstName} ${this.lastName}!`; 
+    }
+};
+
+try {
+    console.log(person.setFirstName("Baptiste").setLastName("Vannesson").sayHello()); // Here is the chain!
+} catch (e) {
+    console.log(e.type + " - " + e.message);
+}