fix: reject loose ranges that collapse to match everything

In loose mode the comparators that fail to parse are filtered out of a
comparator list, and whatever is left becomes the range. When the only
survivor is the any comparator, a typo such as `* (4.1.x  4.1.2)` drops
`(4.1.x` and `4.1.2)` and collapses to the leftover `*`, so the range
silently satisfies every version instead of being rejected. Without
`loose` the same input throws `Invalid comparator: (4.1.x`.

Treat that comparator list as invalid instead, the same way a list with
no valid comparator at all is already treated: the list is dropped, so
other `||` branches still stand on their own and a range left with no
valid branch throws `Invalid SemVer Range`.

Junk sitting next to a comparator that does parse is still tolerated, so
`>=1.2.3 &&&` still yields `>=1.2.3` and `== 1.0.0` still yields
`1.0.0`.

Fixes #387

classes/range.js

@@ -143,10 +143,18 @@ class Range {
 
     if (loose) {
       // in loose mode, throw out any that are not valid comparators
-      rangeList = rangeList.filter(comp => {
+      const filtered = rangeList.filter(comp => {
         debug('loose invalid filter', comp, this.options)
         return !!comp.match(re[t.COMPARATORLOOSE])
       })
+      // dropping invalid comparators must not leave a range that matches
+      // everything: `* (4.1.x 4.1.2)` would collapse to the leftover `*`.
+      // if only the any comparator survives, treat the list as invalid.
+      if (filtered.length !== rangeList.length &&
+          filtered.every(comp => comp === '')) {
+        return []
+      }
+      rangeList = filtered
     }
     debug('range list', rangeList)
 

test/classes/range.js

@@ -3,6 +3,7 @@
 const { test } = require('tap')
 const Range = require('../../classes/range')
 const Comparator = require('../../classes/comparator')
+const satisfies = require('../../functions/satisfies')
 const rangeIntersection = require('../fixtures/range-intersection.js')
 
 const rangeInclude = require('../fixtures/range-include.js')
@@ -38,6 +39,25 @@ test('throw for empty comparator set, even in loose mode', t => {
   t.end()
 })
 
+test('loose mode does not drop comparators down to a match-everything range', t => {
+  // `(4.1.x` and `4.1.2)` used to be filtered out, collapsing the range to the
+  // `*` that was left over, so a typo silently matched every version
+  t.throws(() => new Range('* (4.1.x  4.1.2)', { loose: true }),
+    TypeError('Invalid SemVer Range: * (4.1.x 4.1.2)'))
+  t.equal(satisfies('9.9.9', '* (4.1.x  4.1.2)', { loose: true }), false,
+    'typo range does not match an unrelated version')
+  t.equal(satisfies('4.1.2', '* (4.1.x  4.1.2)', { loose: true }), false,
+    'typo range does not match the version it looks like it means')
+  // only the collapse to `*` is rejected. loose mode still tolerates junk
+  // sitting next to a comparator that does parse, and still tolerates a `||`
+  // branch that is invalid as a whole
+  t.equal(new Range('>=1.2.3 &&&', { loose: true }).range, '>=1.2.3',
+    'junk beside a valid comparator is still dropped')
+  t.equal(new Range('1.2.3 || (foo)', { loose: true }).range, '1.2.3',
+    'wholly invalid union branch is still tolerated')
+  t.end()
+})
+
 test('convert comparator to range', t => {
   const c = new Comparator('>=1.2.3')
   const r = new Range(c)

test/fixtures/range-parse.js

@@ -148,4 +148,12 @@ module.exports = [
   ['1.2.3+sha256.' + 'a'.repeat(200) + '.' + 'b'.repeat(200), '1.2.3', { loose: true }],
   ['1.2.3+' + 'a'.repeat(251) + ' || 2.0.0+' + 'b'.repeat(251),
     '1.2.3||2.0.0', { loose: true }],
+  // dropping unparseable comparators must not leave a match-everything range
+  ['* (4.1.x  4.1.2)', null],
+  ['* (4.1.x  4.1.2)', null, { loose: true }],
+  ['* (foo)', null, { loose: true }],
+  // but loose mode still tolerates junk next to a real comparator, and still
+  // tolerates a `||` branch that is invalid as a whole
+  ['>=1.2.3 &&&', '>=1.2.3', { loose: true }],
+  ['1.2.3 || (foo)', '1.2.3', { loose: true }],
 ]