deps: don't display recursive test dependencies.

You only care about the test dependencies for the specific formula you
are testing right now.

Library/Homebrew/cmd/deps.rb

@@ -18,7 +18,7 @@
 #:    By default, `deps` shows required and recommended dependencies for
 #:    <formulae>. To include the `:build` type dependencies, pass `--include-build`.
 #:    Similarly, pass `--include-optional` to include `:optional` dependencies or
-#:    `--include-test` to include `:test` dependencies.
+#:    `--include-test` to include (non-recursive) `:test` dependencies.
 #:    To skip `:recommended` type dependencies, pass `--skip-recommended`.
 #:    To include requirements in addition to dependencies, pass `--include-requirements`.
 #:
@@ -145,8 +145,11 @@ module Homebrew
         if dep.recommended?
           Dependency.prune if ignores.include?("recommended?") || dependent.build.without?(dep)
         elsif dep.test?
-          next if includes.include?("test?")
-          Dependency.prune
+          if includes.include?("test?")
+            Dependency.keep_but_prune_recursive_deps
+          else
+            Dependency.prune
+          end
         elsif dep.optional?
           Dependency.prune if !includes.include?("optional?") && !dependent.build.with?(dep)
         elsif dep.build?
@@ -157,8 +160,7 @@ module Homebrew
         if req.recommended?
           Requirement.prune if ignores.include?("recommended?") || dependent.build.without?(req)
         elsif req.test?
-          next if includes.include?("test?")
-          Requirement.prune
+          Requirement.prune unless includes.include?("test?")
         elsif req.optional?
           Requirement.prune if !includes.include?("optional?") && !dependent.build.with?(req)
         elsif req.build?

Library/Homebrew/dependency.rb

@@ -83,6 +83,9 @@ class Dependency
       deps.each do |dep|
         next if dependent.name == dep.name
 
+        # we only care about one level of test dependencies.
+        next if dep.test? && @expand_stack.length > 1
+
         case action(dependent, dep, &block)
         when :prune
           next

Library/Homebrew/test/dependency_expansion_spec.rb

@@ -102,12 +102,12 @@ describe Dependency do
   end
 
   it "keeps dependency but prunes recursive dependencies with ::keep_but_prune_recursive_deps" do
-    foo = build_dep(:foo, [:build], bar)
-    baz = build_dep(:baz, [:build])
+    foo = build_dep(:foo, [:test], bar)
+    baz = build_dep(:baz, [:test])
     f = double(name: "f", deps: [foo, baz])
 
     deps = described_class.expand(f) do |_dependent, dep|
-      described_class.keep_but_prune_recursive_deps if dep.build?
+      described_class.keep_but_prune_recursive_deps if dep.test?
     end
 
     expect(deps).to eq([foo, baz])

docs/Manpage.md

@@ -97,7 +97,7 @@ With `--verbose` or `-v`, many commands print extra debugging information. Note
     By default, `deps` shows required and recommended dependencies for
     `formulae`. To include the `:build` type dependencies, pass `--include-build`.
     Similarly, pass `--include-optional` to include `:optional` dependencies or
-    `--include-test` to include `:test` dependencies.
+    `--include-test` to include (non-recursive) `:test` dependencies.
     To skip `:recommended` type dependencies, pass `--skip-recommended`.
     To include requirements in addition to dependencies, pass `--include-requirements`.
 

manpages/brew.1

@@ -107,7 +107,7 @@ If \fB\-\-full\-name\fR is passed, list dependencies by their full name\.
 If \fB\-\-installed\fR is passed, only list those dependencies that are currently installed\.
 .
 .IP
-By default, \fBdeps\fR shows required and recommended dependencies for \fIformulae\fR\. To include the \fB:build\fR type dependencies, pass \fB\-\-include\-build\fR\. Similarly, pass \fB\-\-include\-optional\fR to include \fB:optional\fR dependencies or \fB\-\-include\-test\fR to include \fB:test\fR dependencies\. To skip \fB:recommended\fR type dependencies, pass \fB\-\-skip\-recommended\fR\. To include requirements in addition to dependencies, pass \fB\-\-include\-requirements\fR\.
+By default, \fBdeps\fR shows required and recommended dependencies for \fIformulae\fR\. To include the \fB:build\fR type dependencies, pass \fB\-\-include\-build\fR\. Similarly, pass \fB\-\-include\-optional\fR to include \fB:optional\fR dependencies or \fB\-\-include\-test\fR to include (non\-recursive) \fB:test\fR dependencies\. To skip \fB:recommended\fR type dependencies, pass \fB\-\-skip\-recommended\fR\. To include requirements in addition to dependencies, pass \fB\-\-include\-requirements\fR\.
 .
 .TP
 \fBdeps\fR \fB\-\-tree\fR [\fB\-\-1\fR] [\fIfilters\fR] [\fB\-\-annotate\fR] (\fIformulae\fR|\fB\-\-installed\fR)