Rewrite and reorganize tests

Author: sjsyrek

test/concat-test.js

@@ -0,0 +1,11 @@
+import * as lazy from '../';
+
+describe(`concat()`, function() {
+  const lst1 = lazy.list(1,2,3);
+  const lst2 = lazy.list(4,5,6);
+  const lst3 = lazy.list();
+  const xss = lazy.list(lst1, lst2, lst3);
+  it(`should concatenate (flatten) the elements in a list of lists`, function() {
+    lazy.concat(xss).should.eql(lazy.list(1,2,3,4,5,6));
+  });
+});

test/cons-test.js

@@ -0,0 +1,9 @@
+import * as lazy from '../';
+
+describe(`cons()`, function() {
+  const lst = lazy.list(4,5,6);
+  it(`should create a new list from a head and tail`, function() {
+    lazy.cons(3, lst).should.eql(lazy.list(3,4,5,6));
+    lazy.cons(1, lazy.emptyList).should.eql(lazy.list(1));
+  });
+});

test/cycle-test.js

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+import * as lazy from '../';
+
+describe(`cycle()`, function() {
+  const lst = lazy.list(1,2,3);
+  const cyc = lazy.cycle(lst);
+  it(`should return the infinite repetition of a list`, function() {
+    lazy.take(9, cyc).should.eql(lazy.list(1,2,3,1,2,3,1,2,3));
+    lazy.index(cyc, 100).should.equal(2);
+  });
+  it(`should throw an error if the list is empty`, function() {
+    lazy.cycle.bind(null, lazy.emptyList).should.throw();
+  });
+});

test/drop-test.js

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+import * as lazy from '../';
+
+describe(`drop()`, function() {
+  const lst = lazy.list(1,2,3);
+  it(`should return the suffix of a list after discarding a specified number of values`, function() {
+    lazy.drop(2, lst).should.eql(lazy.list(3));
+  });
+  it(`should return the empty list if the second argument is the empty list`, function() {
+    lazy.drop(2, lazy.list()).should.equal(lazy.emptyList);
+  });
+});

test/dropWhile-test.js

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+import * as lazy from '../';
+
+describe(`dropWhile()`, function() {
+  const lst = lazy.list(1,2,3,4,5,6,7,8,9,10);
+  const f = x => x < 3;
+  it(`should drop values from a list while a given predicate function returns true`, function() {
+    lazy.dropWhile(f, lst).should.eql(lazy.list(3,4,5,6,7,8,9,10));
+  });
+  it(`should return an empty list if the second argument is an empty list`, function() {
+    lazy.dropWhile(f, lazy.emptyList).should.equal(lazy.emptyList);
+  });
+});

test/emptyList-test.js

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+import * as lazy from '../';
+
+describe(`emptyList`, function() {
+  const lst = lazy.list();
+  it(`should be an empty list`, function() {
+    lst.should.equal(lazy.emptyList);
+    lazy.emptyList.should.equal(lst);
+    lazy.length(lazy.emptyList).should.equal(0);
+  });
+});

test/filter-test.js

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+import * as lazy from '../';
+
+describe(`filter()`, function() {
+  const lst = lazy.listRangeBy(0, 50, x => x + 5);
+  const f = x => x % 10 === 0;
+  it(`should return the list of elements in a list for which a function f returns true`, function() {
+    lazy.filter(f, lst).should.eql(lazy.list(0,10,20,30,40,50));
+  });
+});

test/fromArrayToList-test.js

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+import * as lazy from '../';
+
+describe(`fromArrayToList()`, function() {
+  const lst = lazy.list(1,2,3);
+  const arr = [1,2,3];
+  it(`should convert an array into a list`, function() {
+    lazy.fromArrayToList(arr).should.eql(lst);
+  });
+});

test/fromListToArray-test.js

@@ -0,0 +1,9 @@
+import * as lazy from '../';
+
+describe(`fromListToArray()`, function() {
+  const lst = lazy.list(1,2,3);
+  const arr = [1,2,3];
+  it(`should convert a list into an array`, function() {
+    lazy.fromListToArray(lst).should.eql(arr);
+  });
+});

test/fromListToString-test.js

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+import * as lazy from '../';
+
+describe(`fromListToString()`, function() {
+  const str = lazy.list(`a`,`b`,`c`);
+  it(`should convert a list into a string`, function() {
+    lazy.fromListToString(str).should.equal(`abc`);
+  });
+});