Does brew upgrade include brew update?

[jsx97]

Output of brew config

HOMEBREW_VERSION: 4.2.17
ORIGIN: https://github.com/Homebrew/brew
HEAD: 0476c2e5e4f02b409084553896340b2f4ab3352e
Last commit: 5 days ago
Core tap JSON: 08 Apr 09:24 UTC
Core cask tap JSON: 08 Apr 09:24 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_MAKE_JOBS: 10
Homebrew Ruby: 3.1.4 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/bin/ruby
CPU: 10-core 64-bit arm_firestorm_icestorm
Clang: 15.0.0 build 1500
Git: 2.39.3 => /Library/Developer/CommandLineTools/usr/bin/git
Curl: 8.4.0 => /usr/bin/curl
macOS: 14.4.1-arm64
CLT: 15.3.0.0.1.1708646388
Xcode: 15.1
Rosetta 2: false

Output of brew doctor

Your system is ready to brew.

Description of issue

I was told that brew update is already run by brew upgrade in modern Homebrew, so running brew update before brew upgrade is redundant.

Is it really so? I'm asking this because I don't see it mentioned anywhere else. For example, here: https://mac.install.guide/homebrew/4

[SMillerDev]

Yes it is, unless you explicitly disable it.

In general members of the Homebrew organisation are a pretty reliable source of Homebrew actions compared to random guides online. This guide is wrong on various other aspects of Homebrew behaviour too.

[jsx97]

Hi, Sean!

This is true not only for brew upgrade, but also for brew upgrade <formula>, right?

And out of curiosity, what might be a case to prefer brew update on its own, and not as a part of brew upgrade?

[SMillerDev]

This is true not only for brew upgrade, but also for brew upgrade <formula>, right?

Yes

And out of curiosity, what might be a case to prefer brew update on its own, and not as a part of brew upgrade?

If you don't want things to upgrade.