Implement version check and compare functions

Closes: #253

Author: SemenchenkoVitaliy

common.js

@@ -25,6 +25,7 @@ const submodules = [
   'uint64', // Uint64
   'units', // Units conversion
   'utilities', // Common utilities
+  'version', // Version compare and compatibility check
 ].map(path => require('./lib/' + path));
 
 module.exports = Object.assign({}, ...submodules);

lib/version.js

@@ -0,0 +1,57 @@
+'use strict';
+
+// Compare versions
+//   v1 - <string>, with format `a.b.c`
+//   v2 - <string>, with format `x.y.z`
+// Returns: <number>
+//     - `0` if `v1` and `v2` are equal
+//     - `1` if `v1` > `v2`
+//     - `-1` if `v1` < `v2`
+const compareVersions = (v1, v2) => {
+  if (v1 === v2) return 0;
+  const arr1 = v1.split('.').map(num => parseInt(num));
+  const arr2 = v2.split('.').map(num => parseInt(num));
+
+  if (arr1.length < arr2.length) {
+    arr1.push(...Array(arr2.length - arr1.length).fill(0));
+  } else if (arr2.length < arr1.length) {
+    arr2.push(...Array(arr1.length - arr2.length).fill(0));
+  }
+
+  for (let i = 0; i < arr1.length; i++) {
+    if (arr1[i] < arr2[i]) return -1;
+    if (arr1[i] > arr2[i]) return 1;
+  }
+  return 0;
+};
+
+// Check if first version is equal or bigger than the second one
+//   v1 - <string>, with format `a.b.c`
+//   v2 - <string>, with format `x.y.z`
+// Returns: <boolean>
+//     - `true` if `v1` and `v2` are equal or `v1` < `v2`
+//     - `false` if `v1` > `v2`
+const checkVersion = (v1, v2) => compareVersions(v1, v2) <= 0;
+
+// Check if `process.versions.node` is equal or bigger than the specified one
+//   version - <string>, with format `a.b.c`
+// Returns: <boolean>
+//     - `true` if `version` is less or equal than `process.versions.node`
+//     - `false` if `version` is bigger than `process.versions.node`
+const checkNodeVersion = version =>
+  compareVersions(version, process.versions.node) <= 0;
+
+// Check if `process.versions.v8` is equal or bigger than the specified one
+//   version - <string>, with format `a.b.c`
+// Returns: <boolean>
+//     - `true` if `version` is less or equal than `process.versions.v8`
+//     - `false` if `version` is bigger than `process.versions.v8`
+const checkV8Version = version =>
+  compareVersions(version, process.versions.v8) <= 0;
+
+module.exports = {
+  compareVersions,
+  checkVersion,
+  checkNodeVersion,
+  checkV8Version,
+};

test/version.js

@@ -0,0 +1,67 @@
+'use strict';
+
+const metatests = require('metatests');
+const common = require('..');
+
+metatests.case(
+  'Common / version',
+  { common },
+  {
+    'common.compareVersions': [
+      ['0', '0', 0],
+      ['00', '0', 0],
+      ['0', '00', 0],
+      ['0.0', '0', 0],
+      ['0', '0.0', 0],
+
+      ['1', '1', 0],
+      ['01', '1', 0],
+      ['1', '01', 0],
+      ['1.0', '1', 0],
+      ['1', '1.0', 0],
+
+      ['0', '1', -1],
+      ['1.2', '1.3', -1],
+      ['1.2.1', '1.3', -1],
+      ['1.2', '1.2.3', -1],
+      ['1.2', '12', -1],
+      ['2.1', '21', -1],
+
+      ['1', '0', 1],
+      ['1.3', '1.2', 1],
+      ['1.3', '1.2.1', 1],
+      ['1.2.3', '1.2', 1],
+      ['12', '1.2', 1],
+      ['21', '2.1', 1],
+    ],
+    'common.checkVersion': [
+      ['0', '0', true],
+      ['00', '0', true],
+      ['0', '00', true],
+      ['0.0', '0', true],
+      ['0', '0.0', true],
+
+      ['1', '1', true],
+      ['01', '1', true],
+      ['1', '01', true],
+      ['1.0', '1', true],
+      ['1', '1.0', true],
+
+      ['0', '1', true],
+      ['1.2', '1.3', true],
+      ['1.2.1', '1.3', true],
+      ['1.2', '1.2.3', true],
+      ['1.2', '12', true],
+      ['2.1', '21', true],
+
+      ['1', '0', false],
+      ['1.3', '1.2', false],
+      ['1.3', '1.2.1', false],
+      ['1.2.3', '1.2', false],
+      ['12', '1.2', false],
+      ['21', '2.1', false],
+    ],
+    'common.checkNodeVersion': [[process.versions.node, true]],
+    'common.checkV8Version': [[process.versions.v8, true]],
+  }
+);