make `using` required for new licenses

CONTRIBUTING.md

@@ -20,6 +20,7 @@ Choosealicense.com is intended to demystify license choices, not present or cata
    * [GNU's list of free licenses](https://www.gnu.org/licenses/license-list.en.html) (*note: the license must be listed in one of the three "free" categories*)
    * [Open Definition's list of conformant licenses](http://opendefinition.org/licenses/) (non-code)
 3. A [GitHub code search](https://github.com/search?q=MIT+filename%3ALICENSE&type=Code) must reveal at least *1,000* public repositories using the license
+4. 3 notable projects using the license with straightforward LICENSE files which serve as examples newcomers can follow and that could be detected by [licensee](https://github.com/benbalter/licensee) if it knew about the license
 
 If your proposed license meets the above criteria, here's a few other things to keep in mind as you propose the license's addition:
 

README.md

@@ -44,6 +44,7 @@ Licenses sit in the `/_licenses` folder. Each license has YAML front matter desc
 * `source` - The URL to the license source text
 * `description` - A human-readable description of the license
 * `how` - Instructions on how to implement the license
+* `using` - A list of 3 notable projects using the license with straightforward LICENSE files which serve as examples newcomers can follow and that can be detected by [licensee](https://github.com/benbalter/licensee) in the form of `project_name: license_file_url`
 * `permissions` - Bulleted list of permission rules
 * `conditions` - Bulleted list of condition rules
 * `limitations` - Bulleted list of limitation rules
@@ -54,7 +55,6 @@ Licenses sit in the `/_licenses` folder. Each license has YAML front matter desc
 * `hidden` - Whether the license is neither [popular](https://opensource.org/licenses) nor fills out the [spectrum of licenses](http://choosealicense.com/licenses/) from strongly conditional to unconditional (defaults to true)
 * `nickname` - Customary short name if applicable (e.g, GPLv3)
 * `note` - Additional information about the licenses
-* `using` - A list of up to 3 notable projects using the license with straightforward LICENSE files which serve as examples newcomers can follow and that can be detected by [licensee](https://github.com/benbalter/licensee) in the form of `project_name: license_file_url`
 * `redirect_from` - Relative path(s) to redirect to the license from, to prevent breaking old URLs
 
 ### Auto-populated fields

_data/meta.yml

@@ -33,6 +33,10 @@
   description: Bulleted list of limited rules
   required: true
 
+- name: using
+  description: 'A list of 3 notable projects using the license with straightforward LICENSE files which serve as examples newcomers can follow and that can be detected by [licensee](https://github.com/benbalter/licensee) in the form of `project_name: license_file_url`'
+  required: true
+
 # Optional fields
 
 - name: featured
@@ -51,10 +55,6 @@
   description: Additional information about the licenses
   required: false
 
-- name: using
-  description: 'A list of up to 3 notable projects using the license with straightforward LICENSE files which serve as examples newcomers can follow and that can be detected by [licensee](https://github.com/benbalter/licensee) in the form of `project_name: license_file_url`'
-  required: false
-
 - name: redirect_from
   description: Relative path(s) to redirect to the license from, to prevent breaking old URLs
   required: false

_licenses/afl-3.0.txt

@@ -7,6 +7,8 @@ description: The Academic Free License is a variant of the Open Software License
 
 how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of your source code and copy the text of the license into the file. Files licensed under AFL 3.0 must also include the notice "Licensed under the Academic Free License version 3.0" adjacent to the copyright notice.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/agpl-3.0.txt

@@ -12,6 +12,8 @@ how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of
 
 note: The Free Software Foundation recommends taking the additional step of adding a boilerplate notice to the top of each file. The boilerplate can be found at the end of the license.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/artistic-2.0.txt

@@ -8,6 +8,8 @@ description: Heavily favored by the Perl community, the Artistic license require
 
 how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of your source code, and copy the text of the license into the file. Do not replace the copyright notice (year, author), which refers to the license itself, not the licensed project.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/bsd-2-clause.txt

@@ -9,6 +9,8 @@ description: A permissive license that comes in two variants, the <a href="/lice
 
 how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of your source code and copy the text of the license into the file. Replace [year] with the current year and [fullname] with the name (or names) of the copyright holders.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/bsd-3-clause-clear.txt

@@ -7,6 +7,8 @@ description: A variant of the <a href="/licenses/bsd-3-clause/">BSD 3-Clause Lic
 
 how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of your source code and copy the text of the license into the file. Replace [year] with the current year and [fullname] with the name (or names) of the copyright holders. Replace [project] with the project organization, if any, that sponsors this work.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/bsd-3-clause.txt

@@ -8,6 +8,8 @@ description: A permissive license similar to the <a href="/licenses/bsd-2-clause
 
 how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of your source code and copy the text of the license into the file. Replace [year] with the current year and [fullname] with the name (or names) of the copyright holders. Replace [project] with the project organization, if any, that sponsors this work.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/bsl-1.0.txt

@@ -9,6 +9,8 @@ how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of
 
 note: Boost recommends taking the additional step of adding a boilerplate notice to the top of each file. The boilerplate can be found at the [Boost Software License FAQ](http://www.boost.org/users/license.html#FAQ).
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/cc-by-4.0.txt

@@ -7,6 +7,8 @@ description: Permits almost any use subject to providing credit and license noti
 
 how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of your source code and copy the text of the license into the file. It is also acceptable to soley supply a link to a copy of the license, usually to the <a href='https://creativecommons.org/licenses/by/4.0/'>canonical URL for the license</a>.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/cc-by-sa-4.0.txt

@@ -7,6 +7,8 @@ description: Similar to <a href='/licenses/cc-by-4.0/'>CC-BY-4.0</a> but require
 
 how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of your source code and copy the text of the license into the file. It is also acceptable to soley supply a link to a copy of the license, usually to the <a href='https://creativecommons.org/licenses/by-sa/4.0/'>canonical URL for the license</a>.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/cc0-1.0.txt

@@ -10,6 +10,8 @@ how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of
 
 note: Creative Commons recommends taking the additional step of adding a boilerplate notice to the top of each file. The boilerplate can be <a href="https://wiki.creativecommons.org/wiki/CC0_FAQ#May_I_apply_CC0_to_computer_software.3F_If_so.2C_is_there_a_recommended_implementation.3F">found on their website</a>.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/eupl-1.1.txt

@@ -10,6 +10,8 @@ how: Create a text file (typically named COPYING or LICENCE.txt) in the root of
 
 note: The European Commission recommends taking the additional step of adding a [boilerplate notice](https://joinup.ec.europa.eu/sites/default/files/ckeditor_files/files/EUPL%201_1%20Guidelines%20EN%20Joinup.pdf#page=17) to the top of each file.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/lgpl-2.1.txt

@@ -12,6 +12,8 @@ how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of
 
 note: The Free Software Foundation recommends taking the additional step of adding a boilerplate notice to the top of each file. The boilerplate can be found at the end of the license.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/lgpl-3.0.txt

@@ -12,6 +12,8 @@ how: This license is an additional set of permissions to the <a href="/licenses/
 
 note: The Free Software Foundation recommends taking the additional step of adding a boilerplate notice to the top of each file. The boilerplate can be found at the end of the <a href="/licenses/gpl-3.0">GNU GPLv3 license</a>. Insert the word “Lesser” before “General” in all three places in the boilerplate notice to make sure that you refer to the GNU LGPLv3 and not the GNU GPLv3.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/lppl-1.3c.txt

@@ -9,6 +9,8 @@ how: To use this license, place in each of the components of your work both an e
 
 note: An example boilerplate and more information about how to use the license can be found at the end of the license.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/ms-pl.txt

@@ -7,6 +7,8 @@ description: An open source license with a patent grant.
 
 how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of your source code and copy the text of the license into the file.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/ms-rl.txt

@@ -7,6 +7,8 @@ description: An open source license with a patent grant similar to the <a href="
 
 how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of your source code and copy the text of the license into the file.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/ncsa.txt

@@ -13,7 +13,6 @@ using:
  - ROCR-Runtime: https://github.com/RadeonOpenCompute/ROCR-Runtime/blob/master/LICENSE.txt
  - RLTK: https://github.com/chriswailes/RLTK/blob/master/LICENSE
 
-
 permissions:
   - commercial-use
   - modifications

_licenses/ofl-1.1.txt

@@ -10,6 +10,8 @@ how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of
 
 note: This license doesn't require source provision, but recommends it. All files derived from OFL files must remain licensed under the OFL.
 
+using:
+
 permissions:
   - private-use
   - commercial-use

_licenses/wtfpl.txt

@@ -7,6 +7,8 @@ description: The easiest license out there. It gives the user permissions to do
 
 how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of your source code and copy the text of the license into the file.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

_licenses/zlib.txt

@@ -7,6 +7,8 @@ description: A short permissive license, compatible with GPL. Requires altered s
 
 how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of your source code and copy the text of the license into the file. Replace [year] with the current year and [fullname] with the name (or names) of the copyright holders.
 
+using:
+
 permissions:
   - commercial-use
   - modifications

spec/license_meta_spec.rb

@@ -18,6 +18,34 @@ describe 'license meta' do
         missing = required - raw_fields.keys
         expect(missing).to be_empty
       end
+
+      it 'using contains 3 examples' do
+        legacy = [
+          'afl-3.0',
+          'agpl-3.0',
+          'artistic-2.0',
+          'bsd-2-clause',
+          'bsd-3-clause',
+          'bsd-3-clause-clear',
+          'bsl-1.0',
+          'cc0-1.0',
+          'cc-by-4.0',
+          'cc-by-sa-4.0',
+          'eupl-1.1',
+          'gpl-2.0',
+          'lgpl-2.1',
+          'lgpl-3.0',
+          'lppl-1.3c',
+          'ms-pl',
+          'ms-rl',
+          'ofl-1.1',
+          'wtfpl',
+          'zlib'
+        ]
+        skip 'added before 3 using examples required' if legacy.include?(license['slug'])
+        examples = raw_fields['using'] || []
+        expect(examples.length).to eq(3)
+      end
     end
   end
 end