fix(post-asset): strip /\.html?$/ extensions on permalink (#2881)

Fixes #2134
Closes #2551
Closes #2504

Author: JLHwung

lib/models/post_asset.js

@@ -2,6 +2,7 @@
 
 var Schema = require('warehouse').Schema;
 var pathFn = require('path');
+const _ = require('lodash');
 
 module.exports = function(ctx) {
   var PostAsset = new Schema({
@@ -19,7 +20,8 @@ module.exports = function(ctx) {
 
     // PostAsset.path is file path relative to `public_dir`
     // no need to urlescape, #1562
-    return pathFn.join(post.path, this.slug);
+    // strip /\.html?$/ extensions on permalink, #2134
+    return pathFn.join(_.replace(post.path, /\.html?$/, ''), this.slug);
   });
 
   PostAsset.virtual('source').get(function() {

test/scripts/models/post_asset.js

@@ -56,6 +56,48 @@ describe('PostAsset', () => {
     return PostAsset.removeById(data._id);
   }));
 
+  it('path - virtual - when permalink is .html', () => {
+    hexo.config.permalink = ':year/:month/:day/:title.html';
+    return PostAsset.insert({
+      _id: 'source/_posts/test/foo.html',
+      slug: 'foo.htm',
+      post: post._id
+    }).then(data => {
+      data.path.should.eql(pathFn.join(post.path, data.slug));
+      return PostAsset.removeById(data._id);
+    }).finally(() => {
+      hexo.config.permalink = ':year/:month/:day/:title';
+    });
+  });
+
+  it('path - virtual - when permalink is .htm', () => {
+    hexo.config.permalink = ':year/:month/:day/:title.htm';
+    return PostAsset.insert({
+      _id: 'source/_posts/test/foo.htm',
+      slug: 'foo.htm',
+      post: post._id
+    }).then(data => {
+      data.path.should.eql(pathFn.join(post.path, data.slug));
+      return PostAsset.removeById(data._id);
+    }).finally(() => {
+      hexo.config.permalink = ':year/:month/:day/:title';
+    });
+  });
+
+  it('path - virtual - when permalink contains .htm not in the end', () => {
+    hexo.config.permalink = ':year/:month/:day/:title/.htm-foo/';
+    return PostAsset.insert({
+      _id: 'source/_posts/test/foo.html',
+      slug: 'foo.html',
+      post: post._id
+    }).then(data => {
+      data.path.should.eql(pathFn.join(post.path + '.htm-foo/', data.slug));
+      return PostAsset.removeById(data._id);
+    }).finally(() => {
+      hexo.config.permalink = ':year/:month/:day/:title';
+    });
+  });
+
   it('source - virtual', () => PostAsset.insert({
     _id: 'source/_posts/test/foo.jpg',
     slug: 'foo.jpg',