dev-cmd/tests: Add profile option

Library/Homebrew/dev-cmd/tests.rb

@@ -29,6 +29,8 @@ def tests_args
       flag   "--only=",
              description: "Run only <test_script>`_spec.rb`. Appending `:`<line_number> will start at a " \
                           "specific line."
+      flag   "--profile=",
+             description: "Run the test suite serially to find the <n> slowest tests."
       flag   "--seed=",
              description: "Randomise tests with the specified <value> instead of a random seed."
 
@@ -122,6 +124,8 @@ def tests
         end
       end
 
+      parallel = false if args.profile
+
       parallel_rspec_log_name = "parallel_runtime_rspec"
       parallel_rspec_log_name = "#{parallel_rspec_log_name}.generic" if args.generic?
       parallel_rspec_log_name = "#{parallel_rspec_log_name}.online" if args.online?
@@ -157,6 +161,7 @@ def tests
         --require spec_helper
       ]
       bundle_args << "--fail-fast" if args.fail_fast?
+      bundle_args << "--profile" << args.profile if args.profile
 
       # TODO: Refactor and move to extend/os
       # rubocop:disable Homebrew/MoveToExtendOS

completions/bash/brew

@@ -2214,6 +2214,7 @@ _brew_tests() {
       --help
       --online
       --only
+      --profile
       --quiet
       --seed
       --verbose

completions/fish/brew.fish

@@ -1474,6 +1474,7 @@ __fish_brew_complete_arg 'tests' -l generic -d 'Run only OS-agnostic tests'
 __fish_brew_complete_arg 'tests' -l help -d 'Show this message'
 __fish_brew_complete_arg 'tests' -l online -d 'Include tests that use the GitHub API and tests that use any of the taps for official external commands'
 __fish_brew_complete_arg 'tests' -l only -d 'Run only test_script`_spec.rb`. Appending `:`line_number will start at a specific line'
+__fish_brew_complete_arg 'tests' -l profile -d 'Run the test suite serially to find the n slowest tests'
 __fish_brew_complete_arg 'tests' -l quiet -d 'Make some output more quiet'
 __fish_brew_complete_arg 'tests' -l seed -d 'Randomise tests with the specified value instead of a random seed'
 __fish_brew_complete_arg 'tests' -l verbose -d 'Make some output more verbose'

completions/zsh/_brew

@@ -1820,6 +1820,7 @@ _brew_tests() {
     '--help[Show this message]' \
     '--online[Include tests that use the GitHub API and tests that use any of the taps for official external commands]' \
     '(--changed)--only[Run only test_script`_spec.rb`. Appending `:`line_number will start at a specific line]' \
+    '--profile[Run the test suite serially to find the n slowest tests]' \
     '--quiet[Make some output more quiet]' \
     '--seed[Randomise tests with the specified value instead of a random seed]' \
     '--verbose[Make some output more verbose]'

docs/Manpage.md

@@ -1591,6 +1591,8 @@ Run Homebrew's unit and integration tests.
   Exit early on the first failing test.
 * `--only`:
   Run only *`test_script`*`_spec.rb`. Appending `:`*`line_number`* will start at a specific line.
+* `--profile`:
+  Run the test suite serially to find the *`n`* slowest tests.
 * `--seed`:
   Randomise tests with the specified *`value`* instead of a random seed.
 

manpages/brew.1

@@ -2275,6 +2275,10 @@ Exit early on the first failing test\.
 Run only \fItest_script\fR\fB_spec\.rb\fR\. Appending \fB:\fR\fIline_number\fR will start at a specific line\.
 .
 .TP
+\fB\-\-profile\fR
+Run the test suite serially to find the \fIn\fR slowest tests\.
+.
+.TP
 \fB\-\-seed\fR
 Randomise tests with the specified \fIvalue\fR instead of a random seed\.
 .