Add semver.minVersion function.

README.md

@@ -20,6 +20,7 @@ semver.clean('  =v1.2.3   ') // '1.2.3'
 semver.satisfies('1.2.3', '1.x || >=2.5.0 || 5.0.0 - 7.2.3') // true
 semver.gt('1.2.3', '9.8.7') // false
 semver.lt('1.2.3', '9.8.7') // true
+semver.minVersion('>=1.0.0') // '1.0.0'
 semver.valid(semver.coerce('v2')) // '2.0.0'
 semver.valid(semver.coerce('42.6.7.9.3-alpha')) // '42.6.7'
 ```
@@ -368,6 +369,8 @@ strings that they parse.
   that satisfies the range, or `null` if none of them do.
 * `minSatisfying(versions, range)`: Return the lowest version in the list
   that satisfies the range, or `null` if none of them do.
+* `minVersion(range)`: Return the lowest version that can possibly match
+  the given range.
 * `gtr(version, range)`: Return `true` if version is greater than all the
   versions possible in the range.
 * `ltr(version, range)`: Return `true` if version is less than all the

semver.js

@@ -1119,6 +1119,60 @@ function minSatisfying (versions, range, options) {
   return min
 }
 
+exports.minVersion = minVersion
+function minVersion (range, loose) {
+  range = new Range(range, loose)
+
+  var minver = new SemVer('0.0.0')
+  if (range.test(minver)) {
+    return minver
+  }
+
+  minver = new SemVer('0.0.0-0')
+  if (range.test(minver)) {
+    return minver
+  }
+
+  minver = null
+  for (var i = 0; i < range.set.length; ++i) {
+    var comparators = range.set[i]
+
+    comparators.forEach(function (comparator) {
+      // Clone to avoid manipulating the comparator's semver object.
+      var compver = new SemVer(comparator.semver.version)
+      switch (comparator.operator) {
+        case '>':
+          if (compver.prerelease.length === 0) {
+            compver.patch++
+          } else {
+            compver.prerelease.push(0)
+          }
+          compver.raw = compver.format()
+          /* fallthrough */
+        case '':
+        case '>=':
+          if (!minver || gt(minver, compver)) {
+            minver = compver
+          }
+          break
+        case '<':
+        case '<=':
+          /* Ignore maximum versions */
+          break
+        /* istanbul ignore next */
+        default:
+          throw new Error('Unexpected operation: ' + comparator.operator)
+      }
+    })
+  }
+
+  if (minver && range.test(minver)) {
+    return minver
+  }
+
+  return null
+}
+
 exports.validRange = validRange
 function validRange (range, options) {
   try {

test/min-version.js

@@ -0,0 +1,76 @@
+var tap = require('tap')
+var test = tap.test
+var semver = require('../semver.js')
+
+test('\nminimum version in range tests', function (t) {
+  // [range, minimum, loose]
+  [
+    // Stars
+    ['*', '0.0.0'],
+    ['* || >=2', '0.0.0'],
+    ['>=2 || *', '0.0.0'],
+    ['>2 || *', '0.0.0'],
+
+    // equal
+    ['1.0.0', '1.0.0'],
+    ['1.0', '1.0.0'],
+    ['1.0.x', '1.0.0'],
+    ['1.0.*', '1.0.0'],
+    ['1', '1.0.0'],
+    ['1.x.x', '1.0.0'],
+    ['1.x.x', '1.0.0'],
+    ['1.*.x', '1.0.0'],
+    ['1.x.*', '1.0.0'],
+    ['1.x', '1.0.0'],
+    ['1.*', '1.0.0'],
+    ['=1.0.0', '1.0.0'],
+
+    // Tilde
+    ['~1.1.1', '1.1.1'],
+    ['~1.1.1-beta', '1.1.1-beta'],
+    ['~1.1.1 || >=2', '1.1.1'],
+
+    // Carot
+    ['^1.1.1', '1.1.1'],
+    ['^1.1.1-beta', '1.1.1-beta'],
+    ['^1.1.1 || >=2', '1.1.1'],
+
+    // '-' operator
+    ['1.1.1 - 1.8.0', '1.1.1'],
+    ['1.1 - 1.8.0', '1.1.0'],
+
+    // Less / less or equal
+    ['<2', '0.0.0'],
+    ['<0.0.0-beta', '0.0.0-0'],
+    ['<0.0.1-beta', '0.0.0'],
+    ['<2 || >4', '0.0.0'],
+    ['>4 || <2', '0.0.0'],
+    ['<=2 || >=4', '0.0.0'],
+    ['>=4 || <=2', '0.0.0'],
+    ['<0.0.0-beta >0.0.0-alpha', '0.0.0-alpha.0'],
+    ['>0.0.0-alpha <0.0.0-beta', '0.0.0-alpha.0'],
+
+    // Greater than or equal
+    ['>=1.1.1 <2 || >=2.2.2 <2', '1.1.1'],
+    ['>=2.2.2 <2 || >=1.1.1 <2', '1.1.1'],
+
+    // Greater than but not equal
+    ['>1.0.0', '1.0.1'],
+    ['>1.0.0-0', '1.0.0-0.0'],
+    ['>1.0.0-beta', '1.0.0-beta.0'],
+    ['>2 || >1.0.0', '1.0.1'],
+    ['>2 || >1.0.0-0', '1.0.0-0.0'],
+    ['>2 || >1.0.0-beta', '1.0.0-beta.0'],
+
+    // Impossible range
+    ['>4 <3', null]
+  ].forEach(function (tuple) {
+    var range = tuple[0]
+    var version = tuple[1]
+    var loose = tuple[2] || false
+    var msg = 'minVersion(' + range + ', ' + loose + ') = ' + version
+    var min = semver.minVersion(range, loose)
+    t.ok(min === version || (min && min.version === version), msg)
+  })
+  t.end()
+})