From 1b5be21c61c45bf3b770bd8afd0deffd32c5e20b Mon Sep 17 00:00:00 2001
From: fengmk2 <fengmk2@gmail.com>
Date: Thu, 19 Apr 2018 14:35:03 +0800
Subject: [PATCH] feat: support latest-{major} tag as latest version

closes https://github.com/cnpm/npminstall/issues/261
---
 lib/download/npm.js | 18 ++----------
 lib/utils.js        | 33 +++++++++++++++++++++
 test/utils.test.js  | 71 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 106 insertions(+), 16 deletions(-)

diff --git a/lib/download/npm.js b/lib/download/npm.js
index e0e0a43b..9f67eb42 100644
--- a/lib/download/npm.js
+++ b/lib/download/npm.js
@@ -10,7 +10,6 @@ const url = require('url');
 const zlib = require('zlib');
 const destroy = require('destroy');
 const utility = require('utility');
-const semver = require('semver');
 const urlresolve = require('url').resolve;
 const chalk = require('chalk');
 const uuid = require('uuid');
@@ -67,26 +66,13 @@ function* resolve(pkg, options) {
     return options.cache[cacheKey];
   }
 
-  let realPkgVersion;
   let spec = pkg.spec;
   if (spec === '*') {
     spec = 'latest';
   }
-  const distTags = packageMeta['dist-tags'];
-  // try tag first
-  realPkgVersion = distTags[spec];
 
-  if (!realPkgVersion) {
-    const version = semver.valid(spec);
-    const range = semver.validRange(spec);
-    if (semver.satisfies(distTags.latest, spec)) {
-      realPkgVersion = distTags.latest;
-    } else if (version) {
-      realPkgVersion = version;
-    } else if (range) {
-      realPkgVersion = semver.maxSatisfying(packageMeta.allVersions, range);
-    }
-  }
+  const distTags = packageMeta['dist-tags'];
+  let realPkgVersion = utils.findMaxSatisfyingVersion(spec, distTags, packageMeta.allVersions);
 
   if (!realPkgVersion) {
     throw new Error(`[${pkg.displayName}] Can\'t find package ${pkg.name}@${pkg.rawSpec}`);
diff --git a/lib/utils.js b/lib/utils.js
index 7f641485..73dc9c98 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -16,6 +16,7 @@ const homedir = require('node-homedir');
 const fse = require('co-fs-extra');
 const destroy = require('destroy');
 const normalizeData = require('normalize-package-data');
+const semver = require('semver');
 const config = require('./config');
 const get = require('./get');
 
@@ -200,6 +201,38 @@ exports.getMaxRange = function(spec) {
   }
 };
 
+exports.findMaxSatisfyingVersion = function(spec, distTags, allVersions) {
+  // try tag first
+  let realPkgVersion = distTags[spec];
+
+  if (!realPkgVersion) {
+    const version = semver.valid(spec);
+    const range = semver.validRange(spec);
+    if (semver.satisfies(distTags.latest, spec)) {
+      realPkgVersion = distTags.latest;
+    } else if (version) {
+      // use the valid version
+      realPkgVersion = version;
+    } else if (range) {
+      realPkgVersion = semver.maxSatisfying(allVersions, range);
+      if (realPkgVersion) {
+        // try to use latest-{major} tag version on range
+        // ^1.0.1 =range=> get 1.0.3 in (1.0.2, 1.0.3), but latest-1 tag is 1.0.2
+        // finnaly we should use 1.0.2 on ^1.0.1
+        const major = semver.major(realPkgVersion);
+        if (major) {
+          const latestMajorVersion = distTags[`latest-${major}`];
+          if (latestMajorVersion && semver.satisfies(latestMajorVersion, spec)) {
+            realPkgVersion = latestMajorVersion;
+          }
+        }
+      }
+    }
+  }
+
+  return realPkgVersion;
+};
+
 exports.getPackageStorePath = function(storeDir, pkg) {
   // name => _name@1.0.0@name
   // @scope/name => _@scope_name@1.0.0@scope/name
diff --git a/test/utils.test.js b/test/utils.test.js
index 4e1f5aab..1dd387a2 100644
--- a/test/utils.test.js
+++ b/test/utils.test.js
@@ -31,4 +31,75 @@ describe('test/utils.test.js', () => {
       assert(!utils.matchPlatform('win32', [ '!win32', 'win32' ]));
     });
   });
+
+  describe('findMaxSatisfyingVersion()', () => {
+    it('should use vaild version itself', () => {
+      assert(utils.findMaxSatisfyingVersion('1.0.2', {
+        latest: '2.0.0',
+      }, [
+        '1.0.1',
+        '1.0.2',
+        '1.0.3',
+        '2.0.0',
+      ]) === '1.0.2');
+    });
+
+    it('should return undefined when no version match', () => {
+      assert(utils.findMaxSatisfyingVersion('>= 2.0.1 < 3.0.0', {
+        latest: '2.0.0',
+      }, [
+        '1.0.1',
+        '1.0.2',
+        '1.0.3',
+        '2.0.0',
+      ]) === null);
+    });
+
+    it('should use max range version', () => {
+      assert(utils.findMaxSatisfyingVersion('>= 1.0.1 < 2.0.0', {
+        latest: '2.0.0',
+      }, [
+        '1.0.1',
+        '1.0.2',
+        '1.0.3',
+        '2.0.0',
+      ]) === '1.0.3');
+    });
+
+    it('should return latest version', () => {
+      assert(utils.findMaxSatisfyingVersion('latest', {
+        latest: '2.0.0',
+        'latest-1': '1.0.2',
+      }, [
+        '1.0.1',
+        '1.0.2',
+        '1.0.3',
+        '2.0.0',
+      ]) === '2.0.0');
+    });
+
+    it('should support latest version first', () => {
+      assert(utils.findMaxSatisfyingVersion('>= 1.0.1 < 2.0.0', {
+        latest: '1.0.1',
+        'latest-1': '1.0.2',
+      }, [
+        '1.0.1',
+        '1.0.2',
+        '1.0.3',
+        '2.0.0',
+      ]) === '1.0.1');
+    });
+
+    it('should support latest-{major} version', () => {
+      assert(utils.findMaxSatisfyingVersion('>= 1.0.1 < 2.0.0', {
+        latest: '2.0.0',
+        'latest-1': '1.0.2',
+      }, [
+        '1.0.1',
+        '1.0.2',
+        '1.0.3',
+        '2.0.0',
+      ]) === '1.0.2');
+    });
+  });
 });