refs #80: fixes "Unknown language" error

* update to support recent leetcode.com change.

Signed-off-by: Eric Wang <skygragon@gmail.com>

Author: skygragon

lib/config.js

@@ -7,7 +7,7 @@ var DEFAULT_SYS_CONFIG = {
   URL_BASE:            'https://leetcode.com',
   URL_LOGIN:           'https://leetcode.com/accounts/login/',
   URL_PROBLEMS:        'https://leetcode.com/api/problems/$category/',
-  URL_PROBLEM:         'https://leetcode.com/problems/$slug',
+  URL_PROBLEM:         'https://leetcode.com/graphql',
   URL_TEST:            'https://leetcode.com/problems/$slug/interpret_solution/',
   URL_SUBMIT:          'https://leetcode.com/problems/$slug/submit/',
   URL_SUBMISSIONS:     'https://leetcode.com/api/submissions/$slug',

lib/plugins/leetcode.js

@@ -114,45 +114,47 @@ plugin.getCategoryProblems = function(category, cb) {
 
 plugin.getProblem = function(problem, cb) {
   log.debug('running leetcode.getProblem');
-  var opts = makeOpts(problem.link);
-
-  request(opts, function(e, resp, body) {
-    e = checkError(e, resp, 200);
-    if (e) return cb(e);
-
-    var $ = cheerio.load(body);
-    var spans = $('ul[class=side-bar-list] li[class=list-item] span');
-
-    problem.totalAC = $(spans[3]).text();
-    problem.totalSubmit = $(spans[5]).text();
+  var user = session.getUser();
+  if (problem.locked && !user.paid) return cb('failed to load locked problem!');
 
-    // TODO: revisit this if later leetcode remove this element.
-    //       Then we need parse the body to get the description.
-    problem.desc = $('meta[name="description"]').attr('content');
-    problem.desc = he.decode(problem.desc);
+  var opts = makeOpts(config.URL_PROBLEM);
+  opts.headers.Origin = config.URL_BASE;
+  opts.headers.Referer = problem.link;
 
-    var pageData;
-    var r = /(var pageData[^;]+;)/m;
-    var re = body.match(r);
-    if (!re) {
-      var user = session.getUser();
-      if (problem.locked && user.paid) {
-        e = session.errors.EXPIRED;
-      } else {
-        e = 'failed to load' + (problem.locked ? ' locked' : '') + ' problem!';
-      }
-      return cb(e);
-    }
+  opts.json = true;
+  opts.body = {
+    query: [
+      'query getQuestionDetail($titleSlug: String!) {',
+      '  question(titleSlug: $titleSlug) {',
+      '    content',
+      '    stats',
+      '    codeDefinition',
+      '    sampleTestCase',
+      '    enableRunCode',
+      '    metaData',
+      '    discussCategoryId',
+      '  }',
+      '}'
+    ].join('\n'),
+    variables:     {titleSlug: problem.slug},
+    operationName: 'getQuestionDetail'
+  };
 
-    eval(re[1]);
-    problem.templates = pageData.codeDefinition;
-    problem.testcase = pageData.sampleTestCase;
-    problem.testable = pageData.enableRunCode;
-    problem.templateMeta = eval(pageData.metaData);
+  request.post(opts, function(e, resp, body) {
+    e = checkError(e, resp, 200);
+    if (e) return cb(e);
 
-    r = /https:\/\/discuss.leetcode.com\/category\/(\d+)/;
-    re = body.match(r);
-    if (re) problem.discuss = re[1];
+    var q = body.data.question;
+    if (!q) return cb('failed to load problem!');
+
+    problem.totalAC = JSON.parse(q.stats).totalAccepted;
+    problem.totalSubmit = JSON.parse(q.stats).totalSubmission;
+    problem.desc = he.decode(cheerio.load(q.content).root().text());
+    problem.templates = JSON.parse(q.codeDefinition);
+    problem.testcase = q.sampleTestCase;
+    problem.testable = q.enableRunCode;
+    problem.templateMeta = JSON.parse(q.metaData);
+    problem.discuss =  q.discussCategoryId;
 
     return cb(null, problem);
   });

test/mock/find-the-difference.json.20171216

@@ -0,0 +1 @@
+{"data":{"question":{"content":"<p>\r\nGiven two strings <b><i>s</i></b> and <b><i>t</i></b> which consist of only lowercase letters.</p>\r\n\r\n<p>String <b><i>t</i></b> is generated by random shuffling string <b><i>s</i></b> and then add one more letter at a random position.</p>\r\n\r\n<p>Find the letter that was added in <b><i>t</i></b>.</p>\r\n\r\n<p><b>Example:</b>\r\n<pre>\r\nInput:\r\ns = \"abcd\"\r\nt = \"abcde\"\r\n\r\nOutput:\r\ne\r\n\r\nExplanation:\r\n'e' is the letter that was added.\r\n</pre>","stats":"{\"totalAccepted\": \"89.7K\", \"totalSubmission\": \"175.7K\"}","codeDefinition":"[{\"text\": \"C++\", \"value\": \"cpp\", \"defaultCode\": \"class Solution {\\r\\npublic:\\r\\n    char findTheDifference(string s, string t) {\\r\\n        \\r\\n    }\\r\\n};\"}, {\"text\": \"Java\", \"value\": \"java\", \"defaultCode\": \"class Solution {\\r\\n    public char findTheDifference(String s, String t) {\\r\\n        \\r\\n    }\\r\\n}\"}, {\"text\": \"Python\", \"value\": \"python\", \"defaultCode\": \"class Solution(object):\\r\\n    def findTheDifference(self, s, t):\\r\\n        \\\"\\\"\\\"\\r\\n        :type s: str\\r\\n        :type t: str\\r\\n        :rtype: str\\r\\n        \\\"\\\"\\\"\\r\\n        \"}, {\"text\": \"Python3\", \"value\": \"python3\", \"defaultCode\": \"class Solution:\\r\\n    def findTheDifference(self, s, t):\\r\\n        \\\"\\\"\\\"\\r\\n        :type s: str\\r\\n        :type t: str\\r\\n        :rtype: str\\r\\n        \\\"\\\"\\\"\\r\\n        \"}, {\"text\": \"C\", \"value\": \"c\", \"defaultCode\": \"char findTheDifference(char* s, char* t) {\\r\\n    \\r\\n}\"}, {\"text\": \"C#\", \"value\": \"csharp\", \"defaultCode\": \"public class Solution {\\r\\n    public char FindTheDifference(string s, string t) {\\r\\n        \\r\\n    }\\r\\n}\"}, {\"text\": \"JavaScript\", \"value\": \"javascript\", \"defaultCode\": \"/**\\r\\n * @param {string} s\\r\\n * @param {string} t\\r\\n * @return {character}\\r\\n */\\r\\nvar findTheDifference = function(s, t) {\\r\\n    \\r\\n};\"}, {\"text\": \"Ruby\", \"value\": \"ruby\", \"defaultCode\": \"# @param {String} s\\r\\n# @param {String} t\\r\\n# @return {Character}\\r\\ndef find_the_difference(s, t)\\r\\n    \\r\\nend\"}, {\"text\": \"Swift\", \"value\": \"swift\", \"defaultCode\": \"class Solution {\\r\\n    func findTheDifference(_ s: String, _ t: String) -> Character {\\r\\n        \\r\\n    }\\r\\n}\"}, {\"text\": \"Go\", \"value\": \"golang\", \"defaultCode\": \"func findTheDifference(s string, t string) byte {\\r\\n    \\r\\n}\"}, {\"text\": \"Scala\", \"value\": \"scala\", \"defaultCode\": \"object Solution {\\n    def findTheDifference(s: String, t: String): Char = {\\n        \\n    }\\n}\"}, {\"text\": \"Kotlin\", \"value\": \"kotlin\", \"defaultCode\": \"class Solution {\\n    fun findTheDifference(s: String, t: String): Char {\\n        \\n    }\\n}\"}]","sampleTestCase":"\"abcd\"\n\"abcde\"","enableRunCode":true,"metaData":"{\r\n  \"name\": \"findTheDifference\",\r\n  \"params\": [\r\n    {\r\n      \"name\": \"s\",\r\n      \"type\": \"string\"\r\n    },\r\n    {\r\n      \"name\": \"t\",\r\n      \"type\": \"string\"\r\n    }\r\n  ],\r\n  \"return\": {\r\n    \"type\": \"character\"\r\n  }\r\n}","discussCategoryId":"511"}}}

test/plugins/test_leetcode.js

@@ -171,15 +171,19 @@ describe('plugin:leetcode', function() {
   }); // #getCategoryProblems
 
   describe('#getProblem', function() {
+    beforeEach(function() {
+      PROBLEM.locked = false;
+    });
+
     it('should ok', function(done) {
       nock('https://leetcode.com')
-        .get('/problems/find-the-difference')
-        .replyWithFile(200, './test/mock/find-the-difference.html.20170714');
+        .post('/graphql')
+        .replyWithFile(200, './test/mock/find-the-difference.json.20171216');
 
       plugin.getProblem(PROBLEM, function(e, problem) {
         assert.equal(e, null);
-        assert.equal(problem.totalAC, '73.2K');
-        assert.equal(problem.totalSubmit, '142K');
+        assert.equal(problem.totalAC, '89.7K');
+        assert.equal(problem.totalSubmit, '175.7K');
         assert.equal(problem.desc,
           [
             '',
@@ -203,7 +207,7 @@ describe('plugin:leetcode', function() {
             ''
           ].join('\r\n'));
 
-        assert.equal(problem.templates.length, 11);
+        assert.equal(problem.templates.length, 12);
 
         assert.equal(problem.templates[0].value, 'cpp');
         assert.equal(problem.templates[0].text, 'C++');
@@ -221,7 +225,7 @@ describe('plugin:leetcode', function() {
         assert.equal(problem.templates[1].text, 'Java');
         assert.equal(problem.templates[1].defaultCode,
           [
-            'public class Solution {',
+            'class Solution {',
             '    public char findTheDifference(String s, String t) {',
             '        ',
             '    }',
@@ -333,15 +337,23 @@ describe('plugin:leetcode', function() {
             '}'
           ].join('\n'));
 
+        assert.equal(problem.templates[11].value, 'kotlin');
+        assert.equal(problem.templates[11].text, 'Kotlin');
+        assert.equal(problem.templates[11].defaultCode,
+          [
+            'class Solution {',
+            '    fun findTheDifference(s: String, t: String): Char {',
+            '        ',
+            '    }',
+            '}'
+          ].join('\n'));
+
         done();
       });
     });
 
     it('should fail if no permission for locked', function(done) {
       PROBLEM.locked = true;
-      nock('https://leetcode.com')
-        .get('/problems/find-the-difference')
-        .replyWithFile(200, './test/mock/locked.html.20161015');
 
       plugin.getProblem(PROBLEM, function(e, problem) {
         assert.equal(e, 'failed to load locked problem!');
@@ -350,9 +362,7 @@ describe('plugin:leetcode', function() {
     });
 
     it('should fail if session expired', function(done) {
-      nock('https://leetcode.com')
-        .get('/problems/find-the-difference')
-        .reply(403);
+      nock('https://leetcode.com').post('/graphql').reply(403);
 
       plugin.getProblem(PROBLEM, function(e, problem) {
         assert.equal(e, session.errors.EXPIRED);
@@ -361,9 +371,7 @@ describe('plugin:leetcode', function() {
     });
 
     it('should fail if http error', function(done) {
-      nock('https://leetcode.com')
-        .get('/problems/find-the-difference')
-        .reply(500);
+      nock('https://leetcode.com').post('/graphql').reply(500);
 
       plugin.getProblem(PROBLEM, function(e, problem) {
         assert.deepEqual(e, {msg: 'http error', statusCode: 500});
@@ -372,9 +380,7 @@ describe('plugin:leetcode', function() {
     });
 
     it('should fail if unknown error', function(done) {
-      nock('https://leetcode.com')
-        .get('/problems/find-the-difference')
-        .replyWithError('unknown error!');
+      nock('https://leetcode.com').post('/graphql').replyWithError('unknown error!');
 
       plugin.getProblem(PROBLEM, function(e, problem) {
         assert.equal(e.message, 'unknown error!');