fix: optimize Range parsing and formatting

classes/range.js

@@ -1,3 +1,5 @@
+const SPACE_CHARACTERS = /\s+/g
+
 // hoisted class for cyclic dependency
 class Range {
   constructor (range, options) {
@@ -18,7 +20,7 @@ class Range {
       // just put it in the set and return
       this.raw = range.value
       this.set = [[range]]
-      this.format()
+      this.formatted = undefined
       return this
     }
 
@@ -29,10 +31,7 @@ class Range {
     // First reduce all whitespace as much as possible so we do not have to rely
     // on potentially slow regexes like \s*. This is then stored and used for
     // future error messages as well.
-    this.raw = range
-      .trim()
-      .split(/\s+/)
-      .join(' ')
+    this.raw = range.trim().replace(SPACE_CHARACTERS, ' ')
 
     // First, split on ||
     this.set = this.raw
@@ -66,14 +65,29 @@ class Range {
       }
     }
 
-    this.format()
+    this.formatted = undefined
+  }
+
+  get range () {
+    if (this.formatted === undefined) {
+      this.formatted = ''
+      for (let i = 0; i < this.set.length; i++) {
+        if (i > 0) {
+          this.formatted += '||'
+        }
+        const comps = this.set[i]
+        for (let k = 0; k < comps.length; k++) {
+          if (k > 0) {
+            this.formatted += ' '
+          }
+          this.formatted += comps[k].toString().trim()
+        }
+      }
+    }
+    return this.formatted
   }
 
   format () {
-    this.range = this.set
-      .map((comps) => comps.join(' ').trim())
-      .join('||')
-      .trim()
     return this.range
   }
 

test/classes/range.js

@@ -82,6 +82,15 @@ test('tostrings', (t) => {
   t.end()
 })
 
+test('formatted value is calculated lazily and cached', (t) => {
+  const r = new Range('>= v1.2.3')
+  t.equal(r.formatted, undefined)
+  t.equal(r.format(), '>=1.2.3')
+  t.equal(r.formatted, '>=1.2.3')
+  t.equal(r.format(), '>=1.2.3')
+  t.end()
+})
+
 test('ranges intersect', (t) => {
   rangeIntersection.forEach(([r0, r1, expect]) => {
     t.test(`${r0} <~> ${r1}`, t => {