Repository: yt-dlp/yt-dlp
Pull request #10392 (2024-07-08 21:27:32)

[jsinterp] Implement `Function.prototype` resolving for `call` and `apply`
**IMPORTANT**: PRs without the template will be CLOSED

### Description of your *pull request* and other information

<!--

Explanation of your *pull request* in arbitrary form goes here. Please **make sure the description explains the purpose and effect** of your *pull request* and is worded well enough to be understood. Provide as much **context and examples** as possible

-->

Implements prototype resolving for known types that are using `Function.prototype.call` and `Function.prototype.apply`


<details open><summary>Template</summary> <!-- OPEN is intentional -->

<!--

# PLEASE FOLLOW THE GUIDE BELOW

- You will be asked some questions, please read them **carefully** and answer honestly
- Put an `x` into all the boxes `[ ]` relevant to your *pull request* (like [x])
- Use *Preview* tab to see how your *pull request* will actually look like

-->

### Before submitting a *pull request* make sure you have:
- [x] At least skimmed through [contributing guidelines](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#developer-instructions) including [yt-dlp coding conventions](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#yt-dlp-coding-conventions)
- [x] [Searched](https://github.com/yt-dlp/yt-dlp/search?q=is%3Apr&type=Issues) the bugtracker for similar pull requests

### In order to be accepted and merged into yt-dlp each piece of code must be in public domain or released under [Unlicense](http://unlicense.org/). Check all of the following options that apply:
- [x] I am the original author of this code and I am willing to release it under [Unlicense](http://unlicense.org/)

### What is the purpose of your *pull request*?
- [x] Core bug fix/improvement

</details>



Patch:
diff --git a/yt_dlp/jsinterp.py b/yt_dlp/jsinterp.py
index a0f32892f..851d4dc7b 100644
--- a/yt_dlp/jsinterp.py
+++ b/yt_dlp/jsinterp.py
@@ -636,6 +636,8 @@ def assertion(cndn, msg):
                     raise self.Exception(f'{member} {msg}', expr)
 
             def eval_method():
+                nonlocal member
+
                 if (variable, member) == ('console', 'debug'):
                     if Debugger.ENABLED:
                         Debugger.write(self.interpret_expression(f'[{arg_str}]', local_vars, allow_recursion))
@@ -644,6 +646,7 @@ def eval_method():
                 types = {
                     'String': str,
                     'Math': float,
+                    'Array': list,
                 }
                 obj = local_vars.get(variable, types.get(variable, NO_DEFAULT))
                 if obj is NO_DEFAULT:
@@ -667,6 +670,21 @@ def eval_method():
                     self.interpret_expression(v, local_vars, allow_recursion)
                     for v in self._separate(arg_str)]
 
+                # Fixup prototype call
+                if isinstance(obj, type) and member.startswith('prototype.'):
+                    new_member, _, func_prototype = member.partition('.')[2].partition('.')
+                    assertion(argvals, 'takes one or more arguments')
+                    assertion(isinstance(argvals[0], obj), f'needs binding to type {obj}')
+                    if func_prototype == 'call':
+                        obj, *argvals = argvals
+                    elif func_prototype == 'apply':
+                        assertion(len(argvals) == 2, 'takes two arguments')
+                        obj, argvals = argvals
+                        assertion(isinstance(argvals, list), 'second argument needs to be a list')
+                    else:
+                        raise self.Exception(f'Unsupported Function method {func_prototype}', expr)
+                    member = new_member
+
                 if obj is str:
                     if member == 'fromCharCode':
                         assertion(argvals, 'takes one or more arguments')


Test patch:
diff --git a/test/test_jsinterp.py b/test/test_jsinterp.py
index 7c556e461..df92c8315 100644
--- a/test/test_jsinterp.py
+++ b/test/test_jsinterp.py
@@ -376,6 +376,33 @@ def test_packed(self):
         jsi = JSInterpreter('''function f(p,a,c,k,e,d){while(c--)if(k[c])p=p.replace(new RegExp('\\b'+c.toString(a)+'\\b','g'),k[c]);return p}''')
         self.assertEqual(jsi.call_function('f', '''h 7=g("1j");7.7h({7g:[{33:"w://7f-7e-7d-7c.v.7b/7a/79/78/77/76.74?t=73&s=2s&e=72&f=2t&71=70.0.0.1&6z=6y&6x=6w"}],6v:"w://32.v.u/6u.31",16:"r%",15:"r%",6t:"6s",6r:"",6q:"l",6p:"l",6o:"6n",6m:\'6l\',6k:"6j",9:[{33:"/2u?b=6i&n=50&6h=w://32.v.u/6g.31",6f:"6e"}],1y:{6d:1,6c:\'#6b\',6a:\'#69\',68:"67",66:30,65:r,},"64":{63:"%62 2m%m%61%5z%5y%5x.u%5w%5v%5u.2y%22 2k%m%1o%22 5t%m%1o%22 5s%m%1o%22 2j%m%5r%22 16%m%5q%22 15%m%5p%22 5o%2z%5n%5m%2z",5l:"w://v.u/d/1k/5k.2y",5j:[]},\'5i\':{"5h":"5g"},5f:"5e",5d:"w://v.u",5c:{},5b:l,1x:[0.25,0.50,0.75,1,1.25,1.5,2]});h 1m,1n,5a;h 59=0,58=0;h 7=g("1j");h 2x=0,57=0,56=0;$.55({54:{\'53-52\':\'2i-51\'}});7.j(\'4z\',6(x){c(5>0&&x.1l>=5&&1n!=1){1n=1;$(\'q.4y\').4x(\'4w\')}});7.j(\'13\',6(x){2x=x.1l});7.j(\'2g\',6(x){2w(x)});7.j(\'4v\',6(){$(\'q.2v\').4u()});6 2w(x){$(\'q.2v\').4t();c(1m)19;1m=1;17=0;c(4s.4r===l){17=1}$.4q(\'/2u?b=4p&2l=1k&4o=2t-4n-4m-2s-4l&4k=&4j=&4i=&17=\'+17,6(2r){$(\'#4h\').4g(2r)});$(\'.3-8-4f-4e:4d("4c")\').2h(6(e){2q();g().4b(0);g().4a(l)});6 2q(){h $14=$("<q />").2p({1l:"49",16:"r%",15:"r%",48:0,2n:0,2o:47,46:"45(10%, 10%, 10%, 0.4)","44-43":"42"});$("<41 />").2p({16:"60%",15:"60%",2o:40,"3z-2n":"3y"}).3x({\'2m\':\'/?b=3w&2l=1k\',\'2k\':\'0\',\'2j\':\'2i\'}).2f($14);$14.2h(6(){$(3v).3u();g().2g()});$14.2f($(\'#1j\'))}g().13(0);}6 3t(){h 9=7.1b(2e);2d.2c(9);c(9.n>1){1r(i=0;i<9.n;i++){c(9[i].1a==2e){2d.2c(\'!!=\'+i);7.1p(i)}}}}7.j(\'3s\',6(){g().1h("/2a/3r.29","3q 10 28",6(){g().13(g().27()+10)},"2b");$("q[26=2b]").23().21(\'.3-20-1z\');g().1h("/2a/3p.29","3o 10 28",6(){h 12=g().27()-10;c(12<0)12=0;g().13(12)},"24");$("q[26=24]").23().21(\'.3-20-1z\');});6 1i(){}7.j(\'3n\',6(){1i()});7.j(\'3m\',6(){1i()});7.j("k",6(y){h 9=7.1b();c(9.n<2)19;$(\'.3-8-3l-3k\').3j(6(){$(\'#3-8-a-k\').1e(\'3-8-a-z\');$(\'.3-a-k\').p(\'o-1f\',\'11\')});7.1h("/3i/3h.3g","3f 3e",6(){$(\'.3-1w\').3d(\'3-8-1v\');$(\'.3-8-1y, .3-8-1x\').p(\'o-1g\',\'11\');c($(\'.3-1w\').3c(\'3-8-1v\')){$(\'.3-a-k\').p(\'o-1g\',\'l\');$(\'.3-a-k\').p(\'o-1f\',\'l\');$(\'.3-8-a\').1e(\'3-8-a-z\');$(\'.3-8-a:1u\').3b(\'3-8-a-z\')}3a{$(\'.3-a-k\').p(\'o-1g\',\'11\');$(\'.3-a-k\').p(\'o-1f\',\'11\');$(\'.3-8-a:1u\').1e(\'3-8-a-z\')}},"39");7.j("38",6(y){1d.37(\'1c\',y.9[y.36].1a)});c(1d.1t(\'1c\')){35("1s(1d.1t(\'1c\'));",34)}});h 18;6 1s(1q){h 9=7.1b();c(9.n>1){1r(i=0;i<9.n;i++){c(9[i].1a==1q){c(i==18){19}18=i;7.1p(i)}}}}',36,270,'|||jw|||function|player|settings|tracks|submenu||if||||jwplayer|var||on|audioTracks|true|3D|length|aria|attr|div|100|||sx|filemoon|https||event|active||false|tt|seek|dd|height|width|adb|current_audio|return|name|getAudioTracks|default_audio|localStorage|removeClass|expanded|checked|addButton|callMeMaybe|vplayer|0fxcyc2ajhp1|position|vvplay|vvad|220|setCurrentAudioTrack|audio_name|for|audio_set|getItem|last|open|controls|playbackRates|captions|rewind|icon|insertAfter||detach|ff00||button|getPosition|sec|png|player8|ff11|log|console|track_name|appendTo|play|click|no|scrolling|frameborder|file_code|src|top|zIndex|css|showCCform|data|1662367683|383371|dl|video_ad|doPlay|prevt|mp4|3E||jpg|thumbs|file|300|setTimeout|currentTrack|setItem|audioTrackChanged|dualSound|else|addClass|hasClass|toggleClass|Track|Audio|svg|dualy|images|mousedown|buttons|topbar|playAttemptFailed|beforePlay|Rewind|fr|Forward|ff|ready|set_audio_track|remove|this|upload_srt|prop|50px|margin|1000001|iframe|center|align|text|rgba|background|1000000|left|absolute|pause|setCurrentCaptions|Upload|contains|item|content|html|fviews|referer|prem|embed|3e57249ef633e0d03bf76ceb8d8a4b65|216|83|hash|view|get|TokenZir|window|hide|show|complete|slow|fadeIn|video_ad_fadein|time||cache|Cache|Content|headers|ajaxSetup|v2done|tott|vastdone2|vastdone1|vvbefore|playbackRateControls|cast|aboutlink|FileMoon|abouttext|UHD|1870|qualityLabels|sites|GNOME_POWER|link|2Fiframe|3C|allowfullscreen|22360|22640|22no|marginheight|marginwidth|2FGNOME_POWER|2F0fxcyc2ajhp1|2Fe|2Ffilemoon|2F|3A||22https|3Ciframe|code|sharing|fontOpacity|backgroundOpacity|Tahoma|fontFamily|303030|backgroundColor|FFFFFF|color|userFontScale|thumbnails|kind|0fxcyc2ajhp10000|url|get_slides|start|startparam|none|preload|html5|primary|hlshtml|androidhls|duration|uniform|stretching|0fxcyc2ajhp1_xt|image|2048|sp|6871|asn|127|srv|43200|_g3XlBcu2lmD9oDexD2NLWSmah2Nu3XcDrl93m9PwXY|m3u8||master|0fxcyc2ajhp1_x|00076|01|hls2|to|s01|delivery|storage|moon|sources|setup'''.split('|')))
 
+    def test_join(self):
+        test_input = list('test')
+        tests = [
+            'function f(a, b){return a.join(b)}',
+            'function f(a, b){return Array.prototype.join.call(a, b)}',
+            'function f(a, b){return Array.prototype.join.apply(a, [b])}',
+        ]
+        for test in tests:
+            jsi = JSInterpreter(test)
+            self._test(jsi, 'test', args=[test_input, ''])
+            self._test(jsi, 't-e-s-t', args=[test_input, '-'])
+            self._test(jsi, '', args=[[], '-'])
+
+    def test_split(self):
+        test_result = list('test')
+        tests = [
+            'function f(a, b){return a.split(b)}',
+            'function f(a, b){return String.prototype.split.call(a, b)}',
+            'function f(a, b){return String.prototype.split.apply(a, [b])}',
+        ]
+        for test in tests:
+            jsi = JSInterpreter(test)
+            self._test(jsi, test_result, args=['test', ''])
+            self._test(jsi, test_result, args=['t-e-s-t', '-'])
+            self._test(jsi, [''], args=['', '-'])
+            self._test(jsi, [], args=['', ''])
+
 
 if __name__ == '__main__':
     unittest.main()