Pipeline follows the Groovy language convention of allowing parentheses to be omitted around method arguments.
Many Pipeline steps also use the named-parameter syntax as a shorthand for
creating a Map in Groovy, which uses the syntax [key1: value1, key2: value2].
Making statements like the following functionally equivalent:
git url: 'git://example.com/amazing-project.git', branch: 'main' git([url: 'git://example.com/amazing-project.git', branch: 'main'])
For convenience, when calling steps taking only one parameter (or only one mandatory parameter), the parameter name may be omitted, for example:
sh 'echo hello' /* short form */ sh([script: 'echo hello']) /* long form */