use most permissive license color

lib/licenses.js

@@ -23,6 +23,7 @@ const licenseTypes = {
       'Zlib',
     ],
     color: 'green',
+    priority: '2',
   },
   // copyleft licenses require 'Disclose source' (https://choosealicense.com/appendix/#disclose-source)
   // or 'Same license' (https://choosealicense.com/appendix/#same-license)
@@ -43,24 +44,40 @@ const licenseTypes = {
       'OSL-3.0',
     ],
     color: 'orange',
+    priority: '1',
   },
   // public domain licenses do not require 'License and copyright notice' (https://choosealicense.com/appendix/#include-copyright)
   'public-domain': {
     spdxLicenseIds: ['CC0-1.0', 'Unlicense', 'WTFPL'],
     color: '7cd958',
+    priority: '3',
   },
 }
 
 const licenseToColorMap = {}
 Object.keys(licenseTypes).forEach(licenseType => {
-  const { spdxLicenseIds, color } = licenseTypes[licenseType]
+  const { spdxLicenseIds, color, priority } = licenseTypes[licenseType]
   spdxLicenseIds.forEach(license => {
-    licenseToColorMap[license] = color
+    licenseToColorMap[license] = { color, priority }
   })
 })
 const defaultLicenseColor = 'lightgrey'
-const licenseToColor = spdxId =>
-  licenseToColorMap[spdxId] || defaultLicenseColor
+const licenseToColor = spdxId => {
+  if (!Array.isArray(spdxId)) {
+    return (
+      (licenseToColorMap[spdxId] && licenseToColorMap[spdxId].color) ||
+      defaultLicenseColor
+    )
+  }
+  const licenseType = spdxId
+    .filter(i => licenseToColorMap[i])
+    .map(i => licenseToColorMap[i])
+    .reduce((a, b) => (a.priority > b.priority ? a : b), {
+      color: defaultLicenseColor,
+      priority: 0,
+    })
+  return licenseType.color
+}
 
 function renderLicenseBadge({ license, licenses }) {
   if (licenses === undefined) {
@@ -73,8 +90,6 @@ function renderLicenseBadge({ license, licenses }) {
 
   return {
     message: licenses.join(', '),
-    // TODO This does not provide a color when more than one license is
-    // present. Probably that should be fixed.
     color: licenseToColor(licenses),
   }
 }

lib/licenses.spec.js

@@ -10,6 +10,16 @@ describe('license helpers', function() {
     given('Unlicense').expect('7cd958')
     given('unknown-license').expect('lightgrey')
     given(null).expect('lightgrey')
+
+    given(['CC0-1.0', 'MPL-2.0']).expect('7cd958')
+    given(['MPL-2.0', 'CC0-1.0']).expect('7cd958')
+    given(['MIT', 'MPL-2.0']).expect('green')
+    given(['MPL-2.0', 'MIT']).expect('green')
+    given(['OFL-1.1', 'MPL-2.0']).expect('orange')
+    given(['MPL-2.0', 'OFL-1.1']).expect('orange')
+    given(['CC0-1.0', 'MIT', 'MPL-2.0']).expect('7cd958')
+    given(['UNKNOWN-1.0', 'MIT']).expect('green')
+    given(['UNKNOWN-1.0', 'UNKNOWN-2.0']).expect('lightgrey')
   })
 
   test(renderLicenseBadge, () => {
@@ -30,7 +40,7 @@ describe('license helpers', function() {
     })
     given({ licenses: ['MPL-2.0', 'MIT'] }).expect({
       message: 'MPL-2.0, MIT',
-      color: 'lightgrey',
+      color: 'green',
     })
   })
 })