Merge 138b4ba into de60262

src/linq-to-type.ts

@@ -1,5 +1,4 @@
 Array.prototype.first = function (expression) {
-
     if (this.any()) {
         return expression ? this.filter(expression)[0] : this[0]
     }
@@ -12,7 +11,7 @@ Array.prototype.firstOrDefault = function (expression) {
         return this.first(expression)
     }
 
-    return undefined
+    throw new TypeError("The source sequence is empty.")
 }
 
 Array.prototype.where = function (expression) {
@@ -35,13 +34,15 @@ Array.prototype.elementAt = function (index) {
     if (this.any()) {
         return this[index]
     }
+
     throw new TypeError("The source sequence is empty.")
 }
 
 Array.prototype.elementAtOrDefault = function (index) {
     if (this.any()) {
         return this[index]
     }
+
     throw new TypeError("The source sequence is empty.")
 }
 
@@ -80,13 +81,23 @@ Array.prototype.groupBy = function (group, expression) {
 }
 
 Array.prototype.last = function (expression) {
-    return expression ? this.where(expression).last() : this[this.count() - 1]
+    if (this.any()) {
+        return expression ? this.where(expression).last() : this[this.count() - 1]
+    }
+
+    throw new TypeError("The source sequence is empty.")
 }
 
 Array.prototype.lastOrDefault = function (expression) {
     if (this.any()) {
-        return expression ? this.where(expression).last() : this[this.count() - 1]
+        if (!expression)
+            return this[this.count() - 1]
+
+        let filteredItems = this.where(expression);
+
+        return filteredItems.any() ? this.where(expression).last() : undefined
     }
+
     throw new TypeError("The source sequence is empty.")
 }
 
@@ -137,6 +148,7 @@ Array.prototype.zip = function (second, resultSelector) {
     const result = []
     for (var i = 0; i < until; i++)
         result.push(resultSelector(this[i], second[i]))
+
     return result
 }
 
@@ -148,14 +160,15 @@ Array.prototype.intersect = function (source) {
     if (this.any() && source.any()) {
         return this.where(x => source.contains(x))
     }
+
     throw new TypeError("first or second is null.")
 }
 
 Array.prototype.groupJoin = function (inner, outerKeySelector, innerKeySelector, resultSelector) {
-
     if (this.any() || inner.any()) {
         return this.select((x, y) => resultSelector(x, inner.where(a => outerKeySelector(x) === innerKeySelector(a))));
     }
+
     throw new TypeError("outer or inner or outerKeySelector or innerKeySelector or resultSelector is null.")
 }
 

test/linq-to-type.spec.ts

@@ -83,14 +83,24 @@ describe('First test', () => {
 describe('FirstOrDefault test', () => {
     describe('Given an array', () => {
         describe('and you are asked the first or default item in the collection', () => {
-            it('should return the first item', () => {
-                let result = items.firstOrDefault(x => x == 1)
+            it('should return the first item that meets the expression', () => {
+                let result = items.firstOrDefault(x => x > 1)
+                expect(result).to.be.eq(2)
+            })
+
+            it('sould return default value if not meet the expression', () => {
+                let result = items.firstOrDefault(x => x > 10)
+                expect(result).to.be.eq(undefined)
+            })
+
+            it('should return the first item without an expression', () => {
+                let result = items.firstOrDefault()
                 expect(result).to.be.eq(1)
             })
-            it('should return undefined if collection is empty', () => {
+
+            it('should throws an exception if the collection is empty', () => {
                 let items = []
-                let result = items.firstOrDefault(x => x > 1)
-                expect(result).to.be.undefined
+                expect(() => items.firstOrDefault()).to.throws(TypeError, 'The source sequence is empty.')
             })
         })
     })
@@ -319,14 +329,19 @@ describe('Last test', () => {
     describe('Given an array', () => {
         describe('and requests the last item of the collection', () => {
             it('should return the last item that meets the expression', () => {
-                let result = items.last(x => x > 7)
-                expect(result).to.be.eq(8)
+                let result = items.last(x => x < 7)
+                expect(result).to.be.eq(6)
             })
 
             it('should return the last item without an expression', () => {
                 let result = items.last()
                 expect(result).to.be.eq(8)
             })
+
+            it('should throws an exception if the collection is empty', () => {
+                let items = []
+                expect(() => items.last()).to.throws(TypeError, 'The source sequence is empty.')
+            })
         })
     })
 })
@@ -335,16 +350,15 @@ describe('LastOrDefault test', () => {
     describe('Given an array', () => {
         describe('and requests the last item of the collection', () => {
             it('should return the last item that meets the expression', () => {
-                let result = items.lastOrDefault(x => x > 7)
-                expect(result).to.be.eq(8)
+                let result = items.lastOrDefault(x => x < 7)
+                expect(result).to.be.eq(6)
             })
 
             it('should return the last item without an expression', () => {
                 let result = items.lastOrDefault()
                 expect(result).to.be.eq(8)
             })
 
-
             it('should throws an exception if the collection is empty', () => {
                 let items = []
                 expect(() => items.lastOrDefault()).to.throws(TypeError, 'The source sequence is empty.')