Add test coverage.

.gitignore

@@ -1,3 +1,4 @@
+.nyc_output
 .vscode
 coverage
 node_modules

lib/index.js

@@ -223,7 +223,9 @@ const Channel = function(length = 0) {
 
       slice: (start, end = Infinity) => {
         const output = Channel();
+
         (async () => {
+          // Consume values before the starting point.
           for (let index = 0; index < start; index++) {
             const value = await readOnly.shift();
 

package.json

@@ -13,14 +13,11 @@
   "dependencies": {},
   "devDependencies": {
     "@nodeguy/assert": "0.1.4",
-    "mocha": "4.0.1"
+    "mocha": "4.0.1",
+    "nyc": "11.3.0"
   },
   "homepage": "https://github.com/NodeGuy/channel",
-  "keywords": [
+  "keywords": ["CSP", "channel", "concurrency"],
-    "CSP",
-    "channel",
-    "concurrency"
-  ],
   "license": "Apache-2.0",
   "main": "lib/index.js",
   "repository": {
@@ -28,6 +25,14 @@
     "url": "git+https://github.com/NodeGuy/channel.git"
   },
   "scripts": {
-    "test": "mocha --recursive"
+    "test": "nyc mocha --recursive"
+  },
+  "nyc": {
+    "check-coverage": true,
+    "branches": 100,
+    "functions": 100,
+    "lines": 100,
+    "statements": 100,
+    "reporter": ["html", "text-summary"]
   }
 }

test/index.js

@@ -136,6 +136,7 @@ describe(`Channel`, function() {
     const channel = Channel();
     Channel.select([channel.push(`cancelled`)]).cancel();
     const closed = Channel.of();
+
     assert.equal(
       await Channel.select([channel.shift(), closed.shift()]),
       closed
@@ -211,6 +212,18 @@ describe(`Channel object`, function() {
       channel.close();
       assert.strictEqual(await channel.shift(), undefined);
     });
+
+    it(`Don't set 'lastValue' to 'undefined' when closing a channel with a cancelled shift.`, async function() {
+      const channel = Channel();
+
+      // Set lastValue to 0.
+      channel.push(0);
+      await channel.shift();
+
+      channel.shift().cancel();
+      channel.close();
+      assert.strictEqual(channel.value(), 0);
+    });
   });
 
   it(`concat`, async function() {
@@ -386,6 +399,15 @@ describe(`Channel object`, function() {
         [1, 2, 3]
       );
     });
+
+    it(`start after end of channel`, async function() {
+      assert.deepEqual(
+        await Channel.of(0, 1, 2)
+          .slice(10)
+          .values(),
+        []
+      );
+    });
   });
 
   it(`some`, async function() {