Fix variable initialization, fix docs, and update tests

Author: kgryte

lib/node_modules/@stdlib/iter/slice/README.md

@@ -103,7 +103,7 @@ var bool = it.next().done;
 // returns true
 ```
 
-If `end` is greater than or equal to `begin`, the returned [iterator][mdn-iterator-protocol] does not return any iterated values.
+If `begin` is greater than or equal to `end`, the returned [iterator][mdn-iterator-protocol] does not return any iterated values.
 
 ```javascript
 var array2iterator = require( '@stdlib/array/to-iterator' );

lib/node_modules/@stdlib/iter/slice/lib/main.js

@@ -91,7 +91,7 @@ function iterSlice( iterator, begin, end ) {
 		M = END;
 	}
 	n = M - N;
-	i = 0;
+	i = -1;
 
 	// Create an iterator protocol-compliant object:
 	iter = {};

lib/node_modules/@stdlib/iter/slice/test/test.js

@@ -29,6 +29,37 @@ var iteratorSymbol = require( '@stdlib/symbol/iterator' );
 var iterSlice = require( './../lib' );
 
 
+// FUNCTIONS //
+
+function createIterator( arr ) {
+	var len;
+	var it;
+	var i;
+
+	len = arr.length;
+	i = -1;
+
+	it = {};
+	it.next = next;
+
+	return it;
+
+	function next() {
+		var out;
+		i += 1;
+		if ( i < len ) {
+			out = {};
+			out.value = arr[ i ];
+			out.done = ( i === len-1 );
+			return out;
+		}
+		return {
+			'done': true
+		};
+	}
+}
+
+
 // TESTS //
 
 tape( 'main export is a function', function test( t ) {
@@ -265,11 +296,9 @@ tape( 'the function returns an iterator protocol-compliant object (finite iterat
 	t.equal( it.next.length, 0, 'has zero arity' );
 
 	actual = [];
-	for ( i = 0; i < values.length; i++ ) {
+	for ( i = 0; i < expected.length; i++ ) {
 		actual.push( it.next() );
 	}
-	actual.push( it.next() );
-
 	t.deepEqual( actual, expected, 'returns expected values' );
 	t.end();
 });
@@ -308,11 +337,9 @@ tape( 'the function returns an iterator protocol-compliant object (begin+<last>)
 	t.equal( it.next.length, 0, 'has zero arity' );
 
 	actual = [];
-	for ( i = 0; i < 4; i++ ) {
+	for ( i = 0; i < expected.length; i++ ) {
 		actual.push( it.next() );
 	}
-	actual.push( it.next() );
-
 	t.deepEqual( actual, expected, 'returns expected values' );
 	t.end();
 });
@@ -351,11 +378,42 @@ tape( 'the function returns an iterator protocol-compliant object (begin+end)',
 	t.equal( it.next.length, 0, 'has zero arity' );
 
 	actual = [];
-	for ( i = 0; i < 4; i++ ) {
+	for ( i = 0; i < expected.length; i++ ) {
 		actual.push( it.next() );
 	}
-	actual.push( it.next() );
+	t.deepEqual( actual, expected, 'returns expected values' );
+	t.end();
+});
 
+tape( 'the function returns an iterator protocol-compliant object (begin+end)', function test( t ) {
+	var expected;
+	var values;
+	var actual;
+	var it;
+	var i;
+
+	values = [ 1, 2, 3, 4 ];
+	expected = [
+		{
+			'value': 2,
+			'done': false
+		},
+		{
+			'value': 3,
+			'done': false
+		},
+		{
+			'done': true
+		}
+	];
+
+	it = iterSlice( array2iterator( values ), 1, 3 );
+	t.equal( it.next.length, 0, 'has zero arity' );
+
+	actual = [];
+	for ( i = 0; i < expected.length; i++ ) {
+		actual.push( it.next() );
+	}
 	t.deepEqual( actual, expected, 'returns expected values' );
 	t.end();
 });
@@ -390,7 +448,7 @@ tape( 'the function returns an iterator protocol-compliant object which returns
 	t.equal( it.next.length, 0, 'has zero arity' );
 
 	actual = [];
-	for ( i = 0; i < 4; i++ ) {
+	for ( i = 0; i < expected.length; i++ ) {
 		actual.push( it.next() );
 	}
 	t.deepEqual( actual, expected, 'returns expected values' );
@@ -415,7 +473,7 @@ tape( 'the function returns an "empty" iterator if the third argument is less th
 	t.equal( it.next.length, 0, 'has zero arity' );
 
 	actual = [];
-	for ( i = 0; i < 1; i++ ) {
+	for ( i = 0; i < expected.length; i++ ) {
 		actual.push( it.next() );
 	}
 	t.deepEqual( actual, expected, 'returns expected values' );
@@ -440,7 +498,7 @@ tape( 'the function returns an "empty" iterator if the third argument is less th
 	t.equal( it.next.length, 0, 'has zero arity' );
 
 	actual = [];
-	for ( i = 0; i < 1; i++ ) {
+	for ( i = 0; i < expected.length; i++ ) {
 		actual.push( it.next() );
 	}
 	t.deepEqual( actual, expected, 'returns expected values' );
@@ -478,39 +536,11 @@ tape( 'the function returns an iterator protocol-compliant object (value+done)',
 	t.equal( it.next.length, 0, 'has zero arity' );
 
 	actual = [];
-	for ( i = 0; i < values.length-3; i++ ) {
+	for ( i = 0; i < expected.length; i++ ) {
 		actual.push( it.next() );
 	}
 	t.deepEqual( actual, expected, 'returns expected values' );
 	t.end();
-
-	function createIterator( arr ) {
-		var len;
-		var it;
-		var i;
-
-		len = arr.length;
-		i = -1;
-
-		it = {};
-		it.next = next;
-
-		return it;
-
-		function next() {
-			var out;
-			i += 1;
-			if ( i < len ) {
-				out = {};
-				out.value = arr[ i ];
-				out.done = ( i === len-1 );
-				return out;
-			}
-			return {
-				'done': true
-			};
-		}
-	}
 });
 
 tape( 'the returned iterator has a `return` method for closing an iterator (no argument)', function test( t ) {