09s-creating-a-meteorite-package.md.erb

---
title: Creating a Meteorite Package
slug: creating-a-meteorite-package
date: 0009/01/02
number: 9.5
sidebar: true
contents: Write a local in-app package.|Write some tests for your package.|Release your package on Atmosphere.
paragraphs: 22
---

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~~~js
Package.describe({
  summary: "A pattern to display application errors to the user"
});

Package.on_use(function (api, where) {
  api.use(['minimongo', 'mongo-livedata', 'templating'], 'client');

  api.add_files(['errors.js', 'errors_list.html', 'errors_list.js'], 'client');
  
  if (api.export) 
    api.export('Errors');
});
~~~
<%= caption "packages/errors/package.js" %>

////

~~~js
Errors = {
  // Local (client-only) collection
  collection: new Meteor.Collection(null),
  
  throw: function(message) {
    Errors.collection.insert({message: message, seen: false})
  },
  clearSeen: function() {
    Errors.collection.remove({seen: true});
  }
};

~~~
<%= caption "packages/errors/errors.js" %>

~~~html
<template name="meteorErrors">
  {{#each errors}}
    {{> meteorError}}
  {{/each}}
</template>

<template name="meteorError">
  <div class="alert alert-error">
    <button type="button" class="close" data-dismiss="alert">&times;</button>
    {{message}}
  </div>
</template>
~~~
<%= caption "packages/errors/errors_list.html" %>

~~~js
Template.meteorErrors.helpers({
  errors: function() {
    return Errors.collection.find();
  }
});

Template.meteorError.rendered = function() {
  var error = this.data;
  Meteor.defer(function() {
    Errors.collection.update(error._id, {$set: {seen: true}});
  });
};
~~~
<%= caption "packages/errors/errors_list.js" %>

### Testing the package out with Microscope

////

~~~bash
$ rm client/helpers/errors.js
$ rm client/views/includes/errors.html
$ rm client/views/includes/errors.js
~~~
<%= caption "removing old files on the bash console" %>

////

~~~js
Router.before(function() { Errors.clearSeen(); });
~~~
<%= caption "lib/router.js" %>

~~~html
  {{> header}}
  {{> meteorErrors}}
~~~
<%= caption "client/views/application/layout.html" %>

~~~js
Meteor.call('post', post, function(error, id) {
  if (error) {
    // display the error to the user
    Errors.throw(error.reason);

~~~
<%= caption "client/views/posts/post_submit.js" %>

~~~js
Posts.update(currentPostId, {$set: postProperties}, function(error) {
  if (error) {
    // display the error to the user
    Errors.throw(error.reason);
~~~
<%= caption "client/views/posts/post_edit.js" %>

<%= scommit "9-5-1", "Created basic errors package and linked it in." %>

////

### Writing tests

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////

~~~js
Tinytest.add("Errors collection works", function(test) {
  test.equal(Errors.collection.find({}).count(), 0);
  
  Errors.throw('A new error!');
  test.equal(Errors.collection.find({}).count(), 1);
  
  Errors.collection.remove({});
});

Tinytest.addAsync("Errors template works", function(test, done) {  
  Errors.throw('A new error!');
  test.equal(Errors.collection.find({seen: false}).count(), 1);
  
  // render the template
  OnscreenDiv(Spark.render(function() {
    return Template.meteorErrors();
  }));
  
  // wait a few milliseconds
  Meteor.setTimeout(function() {
    test.equal(Errors.collection.find({seen: false}).count(), 0);
    test.equal(Errors.collection.find({}).count(), 1);
    Errors.clearSeen();
    
    test.equal(Errors.collection.find({seen: true}).count(), 0);
    done();
  }, 500);
});
~~~
<%= caption "packages/errors/errors_tests.js" %>

////

////

////

~~~js
Package.on_test(function(api) {
  api.use('errors', 'client');
  api.use(['tinytest', 'test-helpers'], 'client');  
  
  api.add_files('errors_tests.js', 'client');
});
~~~
<%= caption "packages/errors/package.js" %>

<%= scommit "9-5-2", "Added tests to the package." %>

////

~~~bash
$ meteor test-packages errors
~~~
<%= caption "Terminal" %>

<%= screenshot "s7-1", "Passing all tests" %>

### Releasing the package

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~~~json
{
  "name": "errors",
  "description": "A pattern to display application errors to the user",
  "homepage": "https://github.com/tmeasday/meteor-errors",
  "author": "Tom Coleman <tom@thesnail.org>",
  "version": "0.1.0",
  "git": "https://github.com/tmeasday/meteor-errors.git",
  "packages": {
  }
}
~~~
<%= caption "packages/errors/smart.json" %>

<%= scommit "9-5-3", "Added a smart.json" %>

////

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~~~bash
$ git init
$ git add -A
$ git commit -m "Created Errors Package"
$ git remote add origin https://github.com/tmeasday/meteor-errors.git
$ git push origin master
$ mrt release .
Done!
~~~
<%= caption "Terminal (run from within `packages/errors`)" %>

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~~~bash
$ rm -r packages/errors
$ mrt add errors
~~~
<%= caption "Terminal (run from the top level of the app)" %>

<%= scommit "9-5-4", "Removed package from development tree." %>

////