Why the dryRun command is used in angular?

Question

Why dryRun command in Angular CLI is used? Actually, it is mentioned "Run through without making any changes" when i give help command what is the meaning of that sentence.

Answer 1

It does exactly what you stated.

"Run through without making any changes"

The command will stop the CLI from making any changes to the file system. So if you are unsure about what some command does, you can test it with --dry-run and not worry it will break something in your application.

Here is the real example of how it's used:

ng g component test-component --dry-run

CREATE src/app/components/test-component/test-component.component.html (29 bytes)
CREATE src/app/components/test-component/test-component.component.spec.ts (678 bytes)
CREATE src/app/components/test-component/test-component.component.ts (301 bytes)
CREATE src/app/components/test-component/test-component.component.scss (0 bytes)
UPDATE src/app/app.module.ts (3181 bytes)

NOTE: The "dryRun" flag means no changes were made.

As you can see I've ran a command which generates a new component. How ever since I added a --dry-run flag to it, it only gave me the output of what would happen if I ran that command without --dry-run. My test-component was not actually created in my project. The last line of the output pretty much explains everything:

NOTE: The "dryRun" flag means no changes were made.

Answer 2

You have to append --dry-run with angular cli commands.

Ex - ng new sample --dry-run

 ng new example --dry-

Simply it just shows (in your cli) what a command does, before it actually does something. It will stop the CLI from making any changes to the file system and it prints everything it would do to your project when you run the command.