Solve exercise triangle

Author: programmiri

triangle/triangle.js

@@ -0,0 +1,35 @@
+class Triangle {
+  constructor(a, b, c) {
+    this.a = a;
+    this.b = b;
+    this.c = c;
+  }
+
+  kind() {
+    if (this.a + this.b + this.c <= 0) {
+      throw new Error();
+    }
+
+    if (this.a < 0 || this.b < 0 || this.c < 0) {
+      throw new Error();
+    }
+
+    if (
+      this.a + this.b < this.c ||
+      this.a + this.c < this.b ||
+      this.b + this.c < this.a
+    ) {
+      throw new Error();
+    }
+
+    if (this.a === this.b && this.b === this.c) {
+      return 'equilateral';
+    }
+    if (this.a === this.b || this.a === this.c || this.b === this.c) {
+      return 'isosceles';
+    }
+    return 'scalene';
+  }
+}
+
+export { Triangle };

triangle/triangle.spec.js

@@ -6,72 +6,72 @@ describe('Triangle', () => {
     expect(triangle.kind()).toEqual('equilateral');
   });
 
-  xtest('larger equilateral triangles also have equal sides', () => {
+  test('larger equilateral triangles also have equal sides', () => {
     const triangle = new Triangle(10, 10, 10);
     expect(triangle.kind()).toEqual('equilateral');
   });
 
-  xtest('isosceles triangles have last two sides equal', () => {
+  test('isosceles triangles have last two sides equal', () => {
     const triangle = new Triangle(3, 4, 4);
     expect(triangle.kind()).toEqual('isosceles');
   });
 
-  xtest('isosceles trianges have first and last sides equal', () => {
+  test('isosceles trianges have first and last sides equal', () => {
     const triangle = new Triangle(4, 3, 4);
     expect(triangle.kind()).toEqual('isosceles');
   });
 
-  xtest('isosceles triangles have two first sides equal', () => {
+  test('isosceles triangles have two first sides equal', () => {
     const triangle = new Triangle(4, 4, 3);
     expect(triangle.kind()).toEqual('isosceles');
   });
 
-  xtest('isosceles triangles have in fact exactly two sides equal', () => {
+  test('isosceles triangles have in fact exactly two sides equal', () => {
     const triangle = new Triangle(10, 10, 2);
     expect(triangle.kind()).toEqual('isosceles');
   });
 
-  xtest('scalene triangles have no equal sides', () => {
+  test('scalene triangles have no equal sides', () => {
     const triangle = new Triangle(3, 4, 5);
     expect(triangle.kind()).toEqual('scalene');
   });
 
-  xtest('scalene triangles have no equal sides at a larger scale too', () => {
+  test('scalene triangles have no equal sides at a larger scale too', () => {
     const triangle = new Triangle(10, 11, 12);
     expect(triangle.kind()).toEqual('scalene');
   });
 
-  xtest('scalene triangles have no equal sides in descending order either', () => {
+  test('scalene triangles have no equal sides in descending order either', () => {
     const triangle = new Triangle(5, 4, 2);
     expect(triangle.kind()).toEqual('scalene');
   });
 
-  xtest('very small triangles are legal', () => {
+  test('very small triangles are legal', () => {
     const triangle = new Triangle(0.4, 0.6, 0.3);
     expect(triangle.kind()).toEqual('scalene');
   });
 
-  xtest('test triangles with no size are illegal', () => {
+  test('test triangles with no size are illegal', () => {
     const triangle = new Triangle(0, 0, 0);
     expect(triangle.kind.bind(triangle)).toThrow();
   });
 
-  xtest('triangles with negative sides are illegal', () => {
+  test('triangles with negative sides are illegal', () => {
     const triangle = new Triangle(3, 4, -5);
     expect(triangle.kind.bind(triangle)).toThrow();
   });
 
-  xtest('triangles violating triangle inequality are illegal', () => {
+  test('triangles violating triangle inequality are illegal', () => {
     const triangle = new Triangle(1, 1, 3);
     expect(triangle.kind.bind(triangle)).toThrow();
   });
 
-  xtest('triangles violating triangle inequality are illegal 2', () => {
+  test('triangles violating triangle inequality are illegal 2', () => {
     const triangle = new Triangle(7, 3, 2);
     expect(triangle.kind.bind(triangle)).toThrow();
   });
 
-  xtest('triangles violating triangle inequality are illegal 3', () => {
+  test('triangles violating triangle inequality are illegal 3', () => {
     const triangle = new Triangle(10, 1, 3);
     expect(triangle.kind.bind(triangle)).toThrow();
   });