To fix Heroku Node.js app deploy failed error code=H10, we should not hard code the port for our app.
For instance, we write
app.listen(process.env.PORT || 3000, () => {});
to call listen with the PORT environment variable or 3000 as a fallback to run with the port from the environment variable or on port 3000 as the default.
To run Sequelize.js delete query with Node.js, we call the destroy method.
For instance, we write
Model.destroy({
where: {
// criteria
},
});
to call Model.destroy with an object with the where property set to the criteria for the entries we want to delete.
To fix sudo node command not found, but node without sudo is working on EC2, we add some symlinks as an admin.
We run
sudo ln -s /usr/local/bin/node /usr/bin/node
sudo ln -s /usr/local/lib/node /usr/lib/node
sudo ln -s /usr/local/bin/npm /usr/bin/npm
sudo ln -s /usr/local/bin/node-waf /usr/bin/node-waf
to add the symlinks for the directories for the Node.js paths in our EC2 virtual machine to run Node as root.
To include Node.js ES6 classes with require, we set module.exports to the class.
Then we can use require to import the class.
For instance, we write
class Animal {
//...
}
module.exports = Animal;
to set module.exports to the Animal class to export the class in Animal.js.
Then we write
const Animal = require("./Animal");
class Dog extends Animal {
//...
}
to require the Animal.js file to import the class.
And then we create the Dog class that inherits from the Animal class.
To suppress output when running npm scripts with JavaScript, we run npm run with the silent option.
For instance, we run
npm run --silent your-script
to run your-script without showing any output with the --silent option.