Summary - npm

Combine install, scripts and semver to set up a project.

Summary - npm

In this group you learned the core tools of npm: installing packages with npm install, defining commands with scripts, separating development packages with devDependencies, version ranges with semver and publishing with npm publish.

You can combine these five tools to set up a real project. For example, you can read a package.json and print the name, version and script count. This is the basic way to inspect a package's structure. Now you will combine all pieces in one piece of code.

Exercise Print name@version and the script count

Define a string named content with the value {"name":"my-lib","version":"1.0.0","scripts":{"start":"node index.js","test":"jest"}}. Parse it into an object with JSON.parse. First print pkg.name + "@" + pkg.version, then print Object.keys(pkg.scripts).length on a separate line, both with console.log.

Show example solution

const content = '{"name":"my-lib","version":"1.0.0","scripts":{"start":"node index.js","test":"jest"}}';
const pkg = JSON.parse(content);
console.log(pkg.name + "@" + pkg.version);
console.log(Object.keys(pkg.scripts).length);

Test yourself

Match each tool to its role

npm install

Installs packages
scripts

Defines commands
devDependencies

Dev packages
semver

Version range
What does scripts.test do in package.json?
```
scripts.test
```
- Deletes test files
- Installs the test package
- The script that npm test runs
- Logs during tests
Show answer

The script that npm test runs — The scripts.test field defines the npm test command.
Complete the tilde range
```
"____1.2.3"
```
Show answer
```
"~1.2.3"
```

Next lesson: The Error class

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