What does — do when running an npm command?

by

-- as an argument on its own is standardized across all UNIX commands: It means that further arguments should be treated as positional arguments, not options. See Guideline 10 in POSIX Utility Syntax Conventions.

To give you a non-NPM-based example, ls -- -l will look for a file named -l, because the -- specified that all subsequent arguments are positional.

In this context, it means that --coverage isn’t an option to npm itself; presumably, then, it’s subsequently read by the test subcommand. For a tool that were following the conventions properly this wouldn’t be necessary, because Guideline 9 specifies that all options shall be given before any arguments (thus that in this context --coverage should be treated as an argument since it comes after the argument test); however, inasmuch as NPM is only partially following the guidelines, this is a foreseeable result.

(Long --option-style options are actually a GNU extension as a whole, so what we have here is a mismash of multiple parsing styles; such is life, unfortunately).

More Related Contents:

  1. Difference between single and double quotes in Bash
  2. Command not found error in Bash variable assignment
  3. How can I use a file in a command and redirect output to the same file without truncating it?
  4. Usage of :- (colon dash) in bash
  5. Why does a space in a variable assignment give an error in Bash? [duplicate]
  6. What is the preferred Bash shebang?
  7. Return value in a Bash function
  8. Shell equality operators (=, ==, -eq)
  9. Indirect variable assignment in bash
  10. Shell script to delete directories older than n days
  11. How to recursively find the latest modified file in a directory?
  12. Bash script compare two date variables [duplicate]
  13. What is the difference between ${var}, “$var”, and “${var}” in the Bash shell?
  14. Remove duplicate entries in a Bash script [duplicate]
  15. Custom Bash prompt is overwriting itself
  16. How to parse a CSV in a Bash script?
  17. How does this bash fork bomb work? [duplicate]
  18. Array intersection in Bash [duplicate]
  19. Modify config file using bash script
  20. Command line to delete all ClearCase view-private files
  21. Bash read ignores leading spaces
  22. What’s a concise way to check that environment variables are set in a Unix shell script?
  23. Using bash to sort data horizontally
  24. Best way to simulate “group by” from bash?
  25. Waiting for background processes to finish before exiting script
  26. Determine if a function exists in bash
  27. Assign a makefile variable value to a bash command result?
  28. Difference between wait and sleep
  29. How to get the first line of a file in a bash script?
  30. find difference between two text files with one item per line [duplicate]

Leave a Comment