From 88eae0633b1bdbdead23bbf638267f53c6c0be9c Mon Sep 17 00:00:00 2001
From: lionellloh <lionell_loh@mymail.sutd.edu.sg>
Date: Thu, 9 Jul 2020 13:01:10 +0800
Subject: [PATCH 01/16] overwrote license attr_rw with a special license method

---
 Library/Homebrew/formula.rb | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index c1e1fc8f0d..6cf72c71a8 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1682,7 +1682,7 @@ class Formula
       "aliases"                  => aliases.sort,
       "versioned_formulae"       => versioned_formulae.map(&:name),
       "desc"                     => desc,
-      "license"                  => license,
+      "license"                  => license.class == String ? [license] : license,
       "homepage"                 => homepage,
       "versions"                 => {
         "stable" => stable&.version&.to_s,
@@ -2210,7 +2210,17 @@ class Formula
     # Shows when running `brew info`.
     #
     # <pre>license "BSD-2-Clause"</pre>
-    attr_rw :license
+    def license args=nil
+      if args.blank?
+        return @licenses
+      else
+        @licenses = args.class == String ? [args] : args
+        puts @licenses
+      # license.
+      end
+    end
+
+    # attr_rw :license
 
     # @!attribute [w] homepage
     # The homepage for the software. Used by users to get more information

From 3d27894015962a780dc3624ea6284eb303824bef Mon Sep 17 00:00:00 2001
From: Lionell Loh Jian An <lionellloh@gmail.com>
Date: Sun, 12 Jul 2020 11:12:10 +0800
Subject: [PATCH 02/16] Apply suggestions from code review

Code review changes

Co-authored-by: Mike McQuaid <mike@mikemcquaid.com>
---
 Library/Homebrew/formula.rb | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 6cf72c71a8..f29013b75f 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -2208,13 +2208,15 @@ class Formula
     # @!attribute [w]
     # The SPDX ID of the open-source license that the formula uses.
     # Shows when running `brew info`.
+    # Multiple licenses means that the software is licensed under multiple licenses.
+    # Do not use multiple licenses if e.g. different parts are under different licenses.
     #
     # <pre>license "BSD-2-Clause"</pre>
-    def license args=nil
-      if args.blank?
+    def license(args = nil)
+      if args.nil?
         return @licenses
       else
-        @licenses = args.class == String ? [args] : args
+        @licenses = Array(args)
         puts @licenses
       # license.
       end

From 9a2f84d4a553b79e5f08e7c440a3d2108033a946 Mon Sep 17 00:00:00 2001
From: lionellloh <lionell_loh@mymail.sutd.edu.sg>
Date: Sun, 12 Jul 2020 11:18:02 +0800
Subject: [PATCH 03/16] Modify to_hash output

---
 Library/Homebrew/formula.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index f29013b75f..38896711bf 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1682,7 +1682,7 @@ class Formula
       "aliases"                  => aliases.sort,
       "versioned_formulae"       => versioned_formulae.map(&:name),
       "desc"                     => desc,
-      "license"                  => license.class == String ? [license] : license,
+      "license"                  => license,
       "homepage"                 => homepage,
       "versions"                 => {
         "stable" => stable&.version&.to_s,

From b91587d1716636b345f13e6829e04ab3a684d5ed Mon Sep 17 00:00:00 2001
From: lionellloh <lionell_loh@mymail.sutd.edu.sg>
Date: Sun, 12 Jul 2020 11:40:02 +0800
Subject: [PATCH 04/16] audit-license: adapt code to use Array of licenses

---
 Library/Homebrew/dev-cmd/audit.rb | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index 2b17297200..4655594847 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -330,16 +330,16 @@ module Homebrew
 
     def audit_license
       if formula.license.present?
-        if @spdx_data["licenses"].any? { |lic| lic["licenseId"] == formula.license }
+        if formula.license.any? { |lic| @spdx_data["licenses"].any? { |standard_lic| standard_lic["licenseId"] == lic } }
           return unless @online
 
           user, repo = get_repo_data(%r{https?://github\.com/([^/]+)/([^/]+)/?.*}) if @new_formula
           return if user.blank?
 
           github_license = GitHub.get_repo_license(user, repo)
-          return if github_license && [formula.license, "NOASSERTION"].include?(github_license)
+          return if github_license && (formula.license +  ["NOASSERTION"]).include?(github_license)
 
-          problem "License mismatch - GitHub license is: #{github_license}, "\
+          problem "License mismatch - GitHub license is: #{Array(github_license)}, "\
                   "but Formulae license states: #{formula.license}."
         else
           problem "#{formula.license} is not a standard SPDX license."

From 557b1d09a2c228a38d9c0792e5685541d0b8a6cc Mon Sep 17 00:00:00 2001
From: lionellloh <lionell_loh@mymail.sutd.edu.sg>
Date: Sun, 12 Jul 2020 12:35:27 +0800
Subject: [PATCH 05/16] correct logic for standard license checking

---
 Library/Homebrew/dev-cmd/audit.rb | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index 4655594847..961f64d3d1 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -330,7 +330,16 @@ module Homebrew
 
     def audit_license
       if formula.license.present?
-        if formula.license.any? { |lic| @spdx_data["licenses"].any? { |standard_lic| standard_lic["licenseId"] == lic } }
+        non_standard_licenses = []
+        formula.license.each do |lic|
+          next if @spdx_data["licenses"].any? { |standard_lic| standard_lic["licenseId"] == lic }
+          non_standard_licenses << lic
+        end
+
+        if non_standard_licenses.present?
+          problem "Formula #{formula.name} contains non standard SPDX license: #{non_standard_licenses} "
+        end
+
           return unless @online
 
           user, repo = get_repo_data(%r{https?://github\.com/([^/]+)/([^/]+)/?.*}) if @new_formula
@@ -341,9 +350,8 @@ module Homebrew
 
           problem "License mismatch - GitHub license is: #{Array(github_license)}, "\
                   "but Formulae license states: #{formula.license}."
-        else
-          problem "#{formula.license} is not a standard SPDX license."
-        end
+
+
       elsif @new_formula
         problem "No license specified for package."
       end

From 14d18a97319348dd2b457c7b279522c19a75c21e Mon Sep 17 00:00:00 2001
From: lionellloh <lionell_loh@mymail.sutd.edu.sg>
Date: Sun, 12 Jul 2020 12:50:50 +0800
Subject: [PATCH 06/16] Forbidden license logic adapt to Array

---
 Library/Homebrew/formula_installer.rb | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index 5ac720ebee..30a572c617 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -1123,18 +1123,18 @@ class FormulaInstaller
       next if @ignore_deps
 
       dep_f = dep.to_formula
-      next unless forbidden_licenses.include? dep_f.license
+      next unless dep_f.license.all?{ |lic| forbidden_licenses.include? lic }
 
       raise CannotInstallFormulaError, <<~EOS
-        The installation of #{formula.name} has a dependency on #{dep.name} with a forbidden license #{dep_f.license}.
+        The installation of #{formula.name} has a dependency on #{dep.name} where all its licenses are forbidden: #{dep_f.license}.
       EOS
     end
     return if @only_deps
 
-    return unless forbidden_licenses.include? formula.license
+    return unless formula.license.all? { |lic| forbidden_licenses.include? lic }
 
     raise CannotInstallFormulaError, <<~EOS
-      #{formula.name} has a forbidden license #{formula.license}.
+      #{formula.name}'s licenses are all forbidden: #{formula.license}.
     EOS
   end
 end

From 797a07d55503388d2ea1e70c2f0ae922138aac31 Mon Sep 17 00:00:00 2001
From: lionellloh <lionell_loh@mymail.sutd.edu.sg>
Date: Sun, 12 Jul 2020 13:18:30 +0800
Subject: [PATCH 07/16] All tests adapted to pass

---
 Library/Homebrew/dev-cmd/audit.rb           | 2 +-
 Library/Homebrew/formula.rb                 | 2 +-
 Library/Homebrew/test/dev-cmd/audit_spec.rb | 6 +++---
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index 961f64d3d1..176aae7720 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -337,7 +337,7 @@ module Homebrew
         end
 
         if non_standard_licenses.present?
-          problem "Formula #{formula.name} contains non standard SPDX license: #{non_standard_licenses} "
+          problem "Formula #{formula.name} contains non standard SPDX license: #{non_standard_licenses}."
         end
 
           return unless @online
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 38896711bf..4cb64c7add 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -2216,7 +2216,7 @@ class Formula
       if args.nil?
         return @licenses
       else
-        @licenses = Array(args)
+        @licenses = Array(args) unless args == ""
         puts @licenses
       # license.
       end
diff --git a/Library/Homebrew/test/dev-cmd/audit_spec.rb b/Library/Homebrew/test/dev-cmd/audit_spec.rb
index 9c78bde60f..368550c320 100644
--- a/Library/Homebrew/test/dev-cmd/audit_spec.rb
+++ b/Library/Homebrew/test/dev-cmd/audit_spec.rb
@@ -120,7 +120,7 @@ module Homebrew
         RUBY
 
         fa.audit_license
-        expect(fa.problems.first).to match "#{custom_spdx_id} is not a standard SPDX license."
+        expect(fa.problems.first).to match "Formula foo contains non standard SPDX license: [\"zzz\"]."
       end
 
       it "verifies that a license info is a standard spdx id" do
@@ -160,8 +160,8 @@ module Homebrew
         RUBY
 
         fa.audit_license
-        expect(fa.problems.first).to match "License mismatch - GitHub license is: GPL-3.0, "\
-        "but Formulae license states: #{standard_mismatch_spdx_id}."
+        expect(fa.problems.first).to match "License mismatch - GitHub license is: [\"GPL-3.0\"], "\
+        "but Formulae license states: #{Array(standard_mismatch_spdx_id)}."
       end
     end
 

From 3982810eab1d04a98d811180608553074883f274 Mon Sep 17 00:00:00 2001
From: lionellloh <lionell_loh@mymail.sutd.edu.sg>
Date: Sun, 12 Jul 2020 13:21:42 +0800
Subject: [PATCH 08/16] brew style --fix

---
 Library/Homebrew/dev-cmd/audit.rb     | 16 ++++++++--------
 Library/Homebrew/formula.rb           |  4 ++--
 Library/Homebrew/formula_installer.rb |  2 +-
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index 176aae7720..c90a229f74 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -333,6 +333,7 @@ module Homebrew
         non_standard_licenses = []
         formula.license.each do |lic|
           next if @spdx_data["licenses"].any? { |standard_lic| standard_lic["licenseId"] == lic }
+
           non_standard_licenses << lic
         end
 
@@ -340,17 +341,16 @@ module Homebrew
           problem "Formula #{formula.name} contains non standard SPDX license: #{non_standard_licenses}."
         end
 
-          return unless @online
+        return unless @online
 
-          user, repo = get_repo_data(%r{https?://github\.com/([^/]+)/([^/]+)/?.*}) if @new_formula
-          return if user.blank?
+        user, repo = get_repo_data(%r{https?://github\.com/([^/]+)/([^/]+)/?.*}) if @new_formula
+        return if user.blank?
 
-          github_license = GitHub.get_repo_license(user, repo)
-          return if github_license && (formula.license +  ["NOASSERTION"]).include?(github_license)
-
-          problem "License mismatch - GitHub license is: #{Array(github_license)}, "\
-                  "but Formulae license states: #{formula.license}."
+        github_license = GitHub.get_repo_license(user, repo)
+        return if github_license && (formula.license + ["NOASSERTION"]).include?(github_license)
 
+        problem "License mismatch - GitHub license is: #{Array(github_license)}, "\
+                "but Formulae license states: #{formula.license}."
 
       elsif @new_formula
         problem "No license specified for package."
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 4cb64c7add..fc790ab329 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -2214,11 +2214,11 @@ class Formula
     # <pre>license "BSD-2-Clause"</pre>
     def license(args = nil)
       if args.nil?
-        return @licenses
+        @licenses
       else
         @licenses = Array(args) unless args == ""
         puts @licenses
-      # license.
+        # license.
       end
     end
 
diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index 30a572c617..7d7938a8fb 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -1123,7 +1123,7 @@ class FormulaInstaller
       next if @ignore_deps
 
       dep_f = dep.to_formula
-      next unless dep_f.license.all?{ |lic| forbidden_licenses.include? lic }
+      next unless dep_f.license.all? { |lic| forbidden_licenses.include? lic }
 
       raise CannotInstallFormulaError, <<~EOS
         The installation of #{formula.name} has a dependency on #{dep.name} where all its licenses are forbidden: #{dep_f.license}.

From 4ff3d63978bd30aa898e53641d5fdbb93ab2e63f Mon Sep 17 00:00:00 2001
From: lionellloh <lionell_loh@mymail.sutd.edu.sg>
Date: Sun, 12 Jul 2020 13:24:51 +0800
Subject: [PATCH 09/16] Clean up

---
 Library/Homebrew/formula.rb | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index fc790ab329..bd87da7562 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -2210,20 +2210,15 @@ class Formula
     # Shows when running `brew info`.
     # Multiple licenses means that the software is licensed under multiple licenses.
     # Do not use multiple licenses if e.g. different parts are under different licenses.
-    #
     # <pre>license "BSD-2-Clause"</pre>
     def license(args = nil)
       if args.nil?
         @licenses
       else
         @licenses = Array(args) unless args == ""
-        puts @licenses
-        # license.
       end
     end
 
-    # attr_rw :license
-
     # @!attribute [w] homepage
     # The homepage for the software. Used by users to get more information
     # about the software and Homebrew maintainers as a point of contact for

From 4a14ae6589c7a7aa111ecac4ce70deccc9c86b1b Mon Sep 17 00:00:00 2001
From: lionellloh <lionell_loh@mymail.sutd.edu.sg>
Date: Fri, 24 Jul 2020 00:10:47 +0800
Subject: [PATCH 10/16] Audit-license: more tests to ensure behaviour

---
 Library/Homebrew/test/dev-cmd/audit_spec.rb | 56 +++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/Library/Homebrew/test/dev-cmd/audit_spec.rb b/Library/Homebrew/test/dev-cmd/audit_spec.rb
index 368550c320..3f28b0bb4c 100644
--- a/Library/Homebrew/test/dev-cmd/audit_spec.rb
+++ b/Library/Homebrew/test/dev-cmd/audit_spec.rb
@@ -86,6 +86,9 @@ module Homebrew
 
       let(:custom_spdx_id) { "zzz" }
       let(:standard_mismatch_spdx_id) { "0BSD" }
+      let(:license_array) { ["0BSD", "GPL-3.0"] }
+      let(:license_array_mismatch) { ["0BSD", "MIT"] }
+      let(:license_array_nonstandard) { ["0BSD", "zzz", "MIT"] }
 
       it "does not check if the formula is not a new formula" do
         fa = formula_auditor "foo", <<~RUBY, spdx_data: spdx_data, new_formula: false
@@ -123,6 +126,18 @@ module Homebrew
         expect(fa.problems.first).to match "Formula foo contains non standard SPDX license: [\"zzz\"]."
       end
 
+      it "detects if license array contains a non-standard spdx-id" do
+        fa = formula_auditor "foo", <<~RUBY, spdx_data: spdx_data, new_formula: true
+          class Foo < Formula
+            url "https://brew.sh/foo-1.0.tgz"
+            license "#{custom_spdx_id}"
+          end
+        RUBY
+
+        fa.audit_license
+        expect(fa.problems.first).to match "Formula foo contains non standard SPDX license: [\"zzz\"]."
+      end
+
       it "verifies that a license info is a standard spdx id" do
         fa = formula_auditor "foo", <<~RUBY, spdx_data: spdx_data, new_formula: true
           class Foo < Formula
@@ -135,6 +150,18 @@ module Homebrew
         expect(fa.problems).to be_empty
       end
 
+      it "verifies that a license array contains only standard spdx id" do
+        fa = formula_auditor "foo", <<~RUBY, spdx_data: spdx_data, new_formula: true
+          class Foo < Formula
+            url "https://brew.sh/foo-1.0.tgz"
+            license #{license_array}
+          end
+        RUBY
+
+        fa.audit_license
+        expect(fa.problems).to be_empty
+      end
+
       it "checks online and verifies that a standard license id is the same "\
         "as what is indicated on its Github repo" do
         fa = formula_auditor "cask", <<~RUBY, spdx_data: spdx_data, online: true, core_tap: true, new_formula: true
@@ -163,6 +190,35 @@ module Homebrew
         expect(fa.problems.first).to match "License mismatch - GitHub license is: [\"GPL-3.0\"], "\
         "but Formulae license states: #{Array(standard_mismatch_spdx_id)}."
       end
+
+      it "checks online and detects that an array of license does not contain "\
+        "what is indicated on its Github repository" do
+        fa = formula_auditor "cask", <<~RUBY, online: true, spdx_data: spdx_data, core_tap: true, new_formula: true
+          class Cask < Formula
+            url "https://github.com/cask/cask/archive/v0.8.4.tar.gz"
+            head "https://github.com/cask/cask.git"
+            license #{license_array_mismatch}
+          end
+        RUBY
+
+        fa.audit_license
+        expect(fa.problems.first).to match "License mismatch - GitHub license is: [\"GPL-3.0\"], "\
+        "but Formulae license states: #{Array(license_array_mismatch)}."
+      end
+
+      it "checks online and verifies that an array of license contains "\
+        "what is indicated on its Github repository" do
+        fa = formula_auditor "cask", <<~RUBY, online: true, spdx_data: spdx_data, core_tap: true, new_formula: true
+          class Cask < Formula
+            url "https://github.com/cask/cask/archive/v0.8.4.tar.gz"
+            head "https://github.com/cask/cask.git"
+            license #{license_array}
+          end
+        RUBY
+
+        fa.audit_license
+        expect(fa.problems).to be_empty
+      end
     end
 
     describe "#audit_file" do

From 721c9b06cdc5b7acaea022d200a9bb5b88cd4874 Mon Sep 17 00:00:00 2001
From: Lionell <lionell_loh@mymail.sutd.edu.sg>
Date: Fri, 24 Jul 2020 21:50:59 +0800
Subject: [PATCH 11/16] audit-license: Small change to use license_array

---
 Library/Homebrew/test/dev-cmd/audit_spec.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Library/Homebrew/test/dev-cmd/audit_spec.rb b/Library/Homebrew/test/dev-cmd/audit_spec.rb
index 3f28b0bb4c..0d1c2097f1 100644
--- a/Library/Homebrew/test/dev-cmd/audit_spec.rb
+++ b/Library/Homebrew/test/dev-cmd/audit_spec.rb
@@ -130,7 +130,7 @@ module Homebrew
         fa = formula_auditor "foo", <<~RUBY, spdx_data: spdx_data, new_formula: true
           class Foo < Formula
             url "https://brew.sh/foo-1.0.tgz"
-            license "#{custom_spdx_id}"
+            license "#{license_array}"
           end
         RUBY
 

From 52321b4fcdf4bea64ca5c57e0171a5d36f37085f Mon Sep 17 00:00:00 2001
From: Lionell Loh Jian An <lionellloh@gmail.com>
Date: Sat, 25 Jul 2020 21:39:29 +0800
Subject: [PATCH 12/16] Apply suggestions from code review

Code review changes

Co-authored-by: Mike McQuaid <mike@mikemcquaid.com>
---
 Library/Homebrew/dev-cmd/audit.rb     | 8 ++++----
 Library/Homebrew/formula.rb           | 2 +-
 Library/Homebrew/formula_installer.rb | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index c90a229f74..b97a79fbc9 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -331,14 +331,14 @@ module Homebrew
     def audit_license
       if formula.license.present?
         non_standard_licenses = []
-        formula.license.each do |lic|
-          next if @spdx_data["licenses"].any? { |standard_lic| standard_lic["licenseId"] == lic }
+        formula.license.each do |license|
+          next if @spdx_data["licenses"].any? { |spdx| spdx["licenseId"] == license }
 
-          non_standard_licenses << lic
+          non_standard_licenses << license
         end
 
         if non_standard_licenses.present?
-          problem "Formula #{formula.name} contains non standard SPDX license: #{non_standard_licenses}."
+          problem "Formula #{formula.name} contains non-standard SPDX licenses: #{non_standard_licenses}."
         end
 
         return unless @online
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index bd87da7562..ab4734cf57 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -2215,7 +2215,7 @@ class Formula
       if args.nil?
         @licenses
       else
-        @licenses = Array(args) unless args == ""
+        @licenses = Array(args)
       end
     end
 
diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index 7d7938a8fb..a288fa5f3e 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -1131,7 +1131,7 @@ class FormulaInstaller
     end
     return if @only_deps
 
-    return unless formula.license.all? { |lic| forbidden_licenses.include? lic }
+    return unless formula.license.all? { |license| forbidden_licenses.include? license }
 
     raise CannotInstallFormulaError, <<~EOS
       #{formula.name}'s licenses are all forbidden: #{formula.license}.

From 0d6ea9e26c17b4776f7707db19ff1eae12456b39 Mon Sep 17 00:00:00 2001
From: Lionell <lionell_loh@mymail.sutd.edu.sg>
Date: Sat, 25 Jul 2020 22:49:57 +0800
Subject: [PATCH 13/16] Updated tests to pass

---
 Library/Homebrew/test/dev-cmd/audit_spec.rb | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/Library/Homebrew/test/dev-cmd/audit_spec.rb b/Library/Homebrew/test/dev-cmd/audit_spec.rb
index 0d1c2097f1..87c65925b3 100644
--- a/Library/Homebrew/test/dev-cmd/audit_spec.rb
+++ b/Library/Homebrew/test/dev-cmd/audit_spec.rb
@@ -94,7 +94,6 @@ module Homebrew
         fa = formula_auditor "foo", <<~RUBY, spdx_data: spdx_data, new_formula: false
           class Foo < Formula
             url "https://brew.sh/foo-1.0.tgz"
-            license ""
           end
         RUBY
 
@@ -106,7 +105,6 @@ module Homebrew
         fa = formula_auditor "foo", <<~RUBY, spdx_data: spdx_data, new_formula: true
           class Foo < Formula
             url "https://brew.sh/foo-1.0.tgz"
-            license ""
           end
         RUBY
 
@@ -123,19 +121,19 @@ module Homebrew
         RUBY
 
         fa.audit_license
-        expect(fa.problems.first).to match "Formula foo contains non standard SPDX license: [\"zzz\"]."
+        expect(fa.problems.first).to match "Formula foo contains non-standard SPDX licenses: [\"zzz\"]."
       end
 
       it "detects if license array contains a non-standard spdx-id" do
         fa = formula_auditor "foo", <<~RUBY, spdx_data: spdx_data, new_formula: true
           class Foo < Formula
             url "https://brew.sh/foo-1.0.tgz"
-            license "#{license_array}"
+            license #{license_array_nonstandard}
           end
         RUBY
 
         fa.audit_license
-        expect(fa.problems.first).to match "Formula foo contains non standard SPDX license: [\"zzz\"]."
+        expect(fa.problems.first).to match "Formula foo contains non-standard SPDX licenses: [\"zzz\"]."
       end
 
       it "verifies that a license info is a standard spdx id" do

From 26c786fc0a99c758c54a3fcd5075acd97985c689 Mon Sep 17 00:00:00 2001
From: lionellloh <lionell_loh@mymail.sutd.edu.sg>
Date: Tue, 28 Jul 2020 20:57:39 +0800
Subject: [PATCH 14/16] double quotes to single quotes

---
 Library/Homebrew/test/dev-cmd/audit_spec.rb | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Library/Homebrew/test/dev-cmd/audit_spec.rb b/Library/Homebrew/test/dev-cmd/audit_spec.rb
index 87c65925b3..c91fee04ef 100644
--- a/Library/Homebrew/test/dev-cmd/audit_spec.rb
+++ b/Library/Homebrew/test/dev-cmd/audit_spec.rb
@@ -86,9 +86,9 @@ module Homebrew
 
       let(:custom_spdx_id) { "zzz" }
       let(:standard_mismatch_spdx_id) { "0BSD" }
-      let(:license_array) { ["0BSD", "GPL-3.0"] }
-      let(:license_array_mismatch) { ["0BSD", "MIT"] }
-      let(:license_array_nonstandard) { ["0BSD", "zzz", "MIT"] }
+      let(:license_array) { ['0BSD', 'GPL-3.0'] }
+      let(:license_array_mismatch) { ['0BSD', 'MIT'] }
+      let(:license_array_nonstandard) { ['0BSD', 'zzz', 'MIT'] }
 
       it "does not check if the formula is not a new formula" do
         fa = formula_auditor "foo", <<~RUBY, spdx_data: spdx_data, new_formula: false

From 67a974455be98319deb2f384750c98e19f9d0571 Mon Sep 17 00:00:00 2001
From: Lionell Loh Jian An <lionellloh@gmail.com>
Date: Tue, 28 Jul 2020 21:01:09 +0800
Subject: [PATCH 15/16] Apply suggestions from code review

Co-authored-by: Mike McQuaid <mike@mikemcquaid.com>
---
 Library/Homebrew/formula_installer.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index a288fa5f3e..c07d59b976 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -1123,7 +1123,7 @@ class FormulaInstaller
       next if @ignore_deps
 
       dep_f = dep.to_formula
-      next unless dep_f.license.all? { |lic| forbidden_licenses.include? lic }
+      next unless dep_f.license.all? { |license| forbidden_licenses.include? license }
 
       raise CannotInstallFormulaError, <<~EOS
         The installation of #{formula.name} has a dependency on #{dep.name} where all its licenses are forbidden: #{dep_f.license}.

From 4f45ddd55b4ed56366b116f8e682055e18793f3c Mon Sep 17 00:00:00 2001
From: lionellloh <lionell_loh@mymail.sutd.edu.sg>
Date: Tue, 28 Jul 2020 21:04:45 +0800
Subject: [PATCH 16/16] brew style --fix

---
 Library/Homebrew/test/dev-cmd/audit_spec.rb | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Library/Homebrew/test/dev-cmd/audit_spec.rb b/Library/Homebrew/test/dev-cmd/audit_spec.rb
index c91fee04ef..87c65925b3 100644
--- a/Library/Homebrew/test/dev-cmd/audit_spec.rb
+++ b/Library/Homebrew/test/dev-cmd/audit_spec.rb
@@ -86,9 +86,9 @@ module Homebrew
 
       let(:custom_spdx_id) { "zzz" }
       let(:standard_mismatch_spdx_id) { "0BSD" }
-      let(:license_array) { ['0BSD', 'GPL-3.0'] }
-      let(:license_array_mismatch) { ['0BSD', 'MIT'] }
-      let(:license_array_nonstandard) { ['0BSD', 'zzz', 'MIT'] }
+      let(:license_array) { ["0BSD", "GPL-3.0"] }
+      let(:license_array_mismatch) { ["0BSD", "MIT"] }
+      let(:license_array_nonstandard) { ["0BSD", "zzz", "MIT"] }
 
       it "does not check if the formula is not a new formula" do
         fa = formula_auditor "foo", <<~RUBY, spdx_data: spdx_data, new_formula: false