Merge pull request #1 from johnhaley81/synchronous-inspection

Added synchronous methods and tests

Author: johnhaley81

lib/core.js

@@ -17,6 +17,37 @@ function Promise(fn) {
     })
   }
 
+  this.state = state;
+
+  this.isFulfilled = function () {
+    debugger;
+    return state === true
+  }
+
+  this.isRejected = function () {
+    return state === false
+  }
+
+  this.isPending = function () {
+    return state === null
+  }
+
+  this.value = function () {
+    if (!this.isFulfilled()) {
+      throw new Error('Cannot get a value of an unfulfilled promise.')
+    }
+
+    return value
+  }
+
+  this.reason = function () {
+    if (!this.isRejected()) {
+      throw new Error('Cannot get a rejection reason of a non-rejected promise.')
+    }
+
+    return reason
+  }
+
   function handle(deferred) {
     if (state === null) {
       deferreds.push(deferred)

test/synchronous-inspection-tests.js

@@ -0,0 +1,154 @@
+var assert = require('better-assert');
+var Promise = require('../');
+
+describe('synchronous-inspection-tests', function () {
+  it('can poll a promise to see if it is resolved', function () {
+    var finished = null;
+    var fulfilledPromise = new Promise(function(resolve, reject) {
+      var interval = setInterval(function() {
+        if (finished !== null) {
+          clearTimeout(interval);
+
+          if (finished) {
+            resolve(true);
+          }
+          else {
+            reject(false);
+          }
+        }
+      }, 10);
+    });
+
+    assert(fulfilledPromise.isPending());
+    assert(!fulfilledPromise.isFulfilled());
+    assert(!fulfilledPromise.isRejected());
+
+    finished = true;
+
+    setTimeout(function () {
+      assert(fulfilledPromise.isFulfilled());
+      assert(!fulfilledPromise.isRejected());
+      assert(fulfilledPromise.value());
+      assert(!fulfilledPromise.isPending());
+    }, 30);
+  });
+
+  it('can poll a promise to see if it is rejected', function () {
+    var finished = null;
+    var fulfilledPromise = new Promise(function(resolve, reject) {
+      var interval = setInterval(function() {
+        if (finished !== null) {
+          clearTimeout(interval);
+
+          if (finished) {
+            resolve(true);
+          }
+          else {
+            reject(false);
+          }
+        }
+      }, 10);
+    });
+
+    assert(fulfilledPromise.isPending());
+    assert(!fulfilledPromise.isFulfilled());
+    assert(!fulfilledPromise.isRejected());
+
+    finished = false;
+
+    setTimeout(function () {
+      assert(!fulfilledPromise.isFulfilled());
+      assert(fulfilledPromise.isRejected());
+      assert(!fulfilledPromise.reason());
+      assert(!fulfilledPromise.isPending());
+    }, 30);
+  });
+
+  it('will throw an error if getting a value of an unfulfilled promise', function () {
+    var finished = null;
+    var fulfilledPromise = new Promise(function(resolve, reject) {
+      var interval = setInterval(function() {
+        if (finished !== null) {
+          clearTimeout(interval);
+
+          if (finished) {
+            resolve(true);
+          }
+          else {
+            reject(false);
+          }
+        }
+      }, 10);
+    });
+
+    assert(fulfilledPromise.isPending());
+    assert(!fulfilledPromise.isFulfilled());
+    assert(!fulfilledPromise.isRejected());
+
+    try {
+      fulfilledPromise.value();
+
+      assert(false);
+    }
+    catch (e) {
+      assert(true);
+    }
+
+    finished = false;
+
+    setTimeout(function () {
+      try {
+        fulfilledPromise.value();
+
+        assert(false);
+      }
+      catch (e) {
+        assert(true);
+      }
+    }, 30);
+  });
+
+  it('will throw an error if getting a reason of a non-rejected promise', function () {
+    var finished = null;
+    var fulfilledPromise = new Promise(function(resolve, reject) {
+      var interval = setInterval(function() {
+        if (finished !== null) {
+          clearTimeout(interval);
+
+          if (finished) {
+            resolve(true);
+          }
+          else {
+            reject(false);
+          }
+        }
+      }, 10);
+    });
+
+    assert(fulfilledPromise.isPending());
+    assert(!fulfilledPromise.isFulfilled());
+    assert(!fulfilledPromise.isRejected());
+
+    try {
+      fulfilledPromise.reason();
+
+      assert(false);
+    }
+    catch (e) {
+      assert(true);
+    }
+
+    finished = true;
+
+    setTimeout(function () {
+      try {
+        fulfilledPromise.reason();
+
+        assert(false);
+      }
+      catch (e) {
+        assert(true);
+      }
+    }, 30);
+  });
+});