Allow requirements to specify a default formula.

This allows default resolution of requirements without user intervention.

Closes #19627.

1 files changed, 3 insertions, 0 deletions

diff --git a/Library/Homebrew/requirements.rb b/Library/Homebrew/requirements.rb
index 29e61b696..bdbe71ee0 100644
--- a/Library/Homebrew/requirements.rb
+++ b/Library/Homebrew/requirements.rb
@@ -19,6 +19,7 @@ end
 
 class MysqlDependency < Requirement
   fatal true
+  default_formula 'mysql'
 
   satisfy { which 'mysql_config' }
 
@@ -40,6 +41,7 @@ end
 
 class PostgresqlDependency < Requirement
   fatal true
+  default_formula 'postgres'
 
   satisfy { which 'pg_config' }
 
@@ -110,6 +112,7 @@ end
 
 class MercurialDependency < Requirement
   fatal true
+  default_formula 'mercurial'
 
   satisfy { which('hg') }