Node.js 为什么我的Heroku日志中没有错误？内部服务器错误

我正在做我的第一个node.js项目，并且正在使用把手进行模板制作。 当我今天通过Heroku部署时，出现了500个错误，在日志中似乎找不到任何东西。在本地一切正常。 我第一次设置了一个新的助手，所以我认为这与此相关。 我将在下面发布我的app.js和日志代码。谢谢

const express = require('express')
const app = express()
const exphbs  = require('express-handlebars');
const path = require('path');
const request = require("request");
const bodyParser = require('body-parser');
const PORT = process.env.PORT || 5000;

const hbs = exphbs.create({

    //create custom helpers here
    helpers:{
        negPosChange: function(value, options){
            if(value > 0) {
                return "<div class=\"positive\">+" + options.fn({test: value}) + "</div>";
              }
              else if(value < 0){
                return "<div class=\"negative\">" + options.fn({test: value}) + "</div>";
              }

              else{
                return "<div>" + options.fn({test: value}) + "</div>";
              }
        }
    }

});

// use body parser middleware -- using express instead for now
app.use(bodyParser.urlencoded({ extended: false }))
app.use(bodyParser.json())
 
 // create call API function
function call_api(finishedAPI, ticker){
    request('https://cloud.iexapis.com/stable/stock/' + ticker + '/quote?token=#APIKEY', function (err, res, body) {
        if (err) {return console.log(err);}
        if(res.statusCode === 200){
      //console.log(body);
        finishedAPI(JSON.parse(body));
        }
    });
}

//Set handlebars middleware
app.engine('handlebars', hbs.engine);
app.set('view engine', 'handlebars');


//Set handlebar index GET route
app.get('/ticker_page.html', function (req, res) {
    call_api(function(doneAPI){
        res.render('ticker_page', {
            stock: doneAPI
        });
    }, 'fb');  
});

//Set handlebar index POST route
app.post('/', function (req, res) {
    call_api(function(doneAPI){
        //posted_stuff = req.body.stock_search;
        res.render('ticker_page', {
            stock: doneAPI,
        });
    }, req.body.stock_search.toLowerCase().trim());  
});

//Create about page route
app.get('/about.html', function (req, res) {
    res.render('about');
});

//Create about page route
app.get('/', function (req, res) {
    res.render('home/home', {layout : 'home-template'});
});


// Set static folder
app.use(express.static(path.join(__dirname, '/')));


app.listen(PORT, () => console.log('Server listening on port' + PORT));

-----> Building on the Heroku-20 stack
-----> Using buildpack: heroku/nodejs
-----> Node.js app detected
       
-----> Creating runtime environment
       
       NPM_CONFIG_LOGLEVEL=error
       NODE_VERBOSE=false
       NODE_ENV=production
       NODE_MODULES_CACHE=true
       
-----> Installing binaries
       engines.node (package.json):  unspecified
       engines.npm (package.json):   unspecified (use default)
       
       Resolving node version 14.x...
       Downloading and installing node 14.16.1...
       Using default npm version: 6.14.12
       
-----> Restoring cache
       - node_modules is checked into source control and cannot be cached
       
-----> Installing dependencies
       Prebuild detected (node_modules already exists)
       Rebuilding any native modules
       
       > nodemon@2.0.7 postinstall /tmp/build_b3975c7b/node_modules/nodemon
       > node bin/postinstall || exit 0
       
       Love nodemon? You can now support the project via the open collective:
        > https://opencollective.com/nodemon/donate
       
       body-parser@1.19.0 /tmp/build_b3975c7b/node_modules/body-parser
       bytes@3.1.0 /tmp/build_b3975c7b/node_modules/bytes
       content-type@1.0.4 /tmp/build_b3975c7b/node_modules/content-type
       debug@2.6.9 /tmp/build_b3975c7b/node_modules/debug
       ms@2.0.0 /tmp/build_b3975c7b/node_modules/ms
       depd@1.1.2 /tmp/build_b3975c7b/node_modules/depd
       http-errors@1.7.2 /tmp/build_b3975c7b/node_modules/http-errors
       inherits@2.0.3 /tmp/build_b3975c7b/node_modules/inherits
       setprototypeof@1.1.1 /tmp/build_b3975c7b/node_modules/setprototypeof
       statuses@1.5.0 /tmp/build_b3975c7b/node_modules/statuses
       toidentifier@1.0.0 /tmp/build_b3975c7b/node_modules/toidentifier
       iconv-lite@0.4.24 /tmp/build_b3975c7b/node_modules/iconv-lite
       safer-buffer@2.1.2 /tmp/build_b3975c7b/node_modules/safer-buffer
       on-finished@2.3.0 /tmp/build_b3975c7b/node_modules/on-finished
       ee-first@1.1.1 /tmp/build_b3975c7b/node_modules/ee-first
       qs@6.7.0 /tmp/build_b3975c7b/node_modules/qs
       raw-body@2.4.0 /tmp/build_b3975c7b/node_modules/raw-body
       unpipe@1.0.0 /tmp/build_b3975c7b/node_modules/unpipe
       type-is@1.6.18 /tmp/build_b3975c7b/node_modules/type-is
       media-typer@0.3.0 /tmp/build_b3975c7b/node_modules/media-typer
       mime-types@2.1.30 /tmp/build_b3975c7b/node_modules/mime-types
       mime-db@1.47.0 /tmp/build_b3975c7b/node_modules/mime-db
       express@4.17.1 /tmp/build_b3975c7b/node_modules/express
       accepts@1.3.7 /tmp/build_b3975c7b/node_modules/accepts
       negotiator@0.6.2 /tmp/build_b3975c7b/node_modules/negotiator
       array-flatten@1.1.1 /tmp/build_b3975c7b/node_modules/array-flatten
       content-disposition@0.5.3 /tmp/build_b3975c7b/node_modules/content-disposition
       safe-buffer@5.1.2 /tmp/build_b3975c7b/node_modules/safe-buffer
       cookie@0.4.0 /tmp/build_b3975c7b/node_modules/cookie
       cookie-signature@1.0.6 /tmp/build_b3975c7b/node_modules/cookie-signature
       encodeurl@1.0.2 /tmp/build_b3975c7b/node_modules/encodeurl
       escape-html@1.0.3 /tmp/build_b3975c7b/node_modules/escape-html
       etag@1.8.1 /tmp/build_b3975c7b/node_modules/etag
       finalhandler@1.1.2 /tmp/build_b3975c7b/node_modules/finalhandler
       parseurl@1.3.3 /tmp/build_b3975c7b/node_modules/parseurl
       fresh@0.5.2 /tmp/build_b3975c7b/node_modules/fresh
       merge-descriptors@1.0.1 /tmp/build_b3975c7b/node_modules/merge-descriptors
       methods@1.1.2 /tmp/build_b3975c7b/node_modules/methods
       path-to-regexp@0.1.7 /tmp/build_b3975c7b/node_modules/path-to-regexp
       proxy-addr@2.0.6 /tmp/build_b3975c7b/node_modules/proxy-addr
       forwarded@0.1.2 /tmp/build_b3975c7b/node_modules/forwarded
       ipaddr.js@1.9.1 /tmp/build_b3975c7b/node_modules/ipaddr.js
       range-parser@1.2.1 /tmp/build_b3975c7b/node_modules/range-parser
       send@0.17.1 /tmp/build_b3975c7b/node_modules/send
       destroy@1.0.4 /tmp/build_b3975c7b/node_modules/destroy
       mime@1.6.0 /tmp/build_b3975c7b/node_modules/mime
       ms@2.1.1 /tmp/build_b3975c7b/node_modules/send/node_modules/ms
       serve-static@1.14.1 /tmp/build_b3975c7b/node_modules/serve-static
       utils-merge@1.0.1 /tmp/build_b3975c7b/node_modules/utils-merge
       vary@1.1.2 /tmp/build_b3975c7b/node_modules/vary
       express-handlebars@5.3.0 /tmp/build_b3975c7b/node_modules/express-handlebars
       glob@7.1.6 /tmp/build_b3975c7b/node_modules/glob
       fs.realpath@1.0.0 /tmp/build_b3975c7b/node_modules/fs.realpath
       inflight@1.0.6 /tmp/build_b3975c7b/node_modules/inflight
       once@1.4.0 /tmp/build_b3975c7b/node_modules/once
       wrappy@1.0.2 /tmp/build_b3975c7b/node_modules/wrappy
       minimatch@3.0.4 /tmp/build_b3975c7b/node_modules/minimatch
       brace-expansion@1.1.11 /tmp/build_b3975c7b/node_modules/brace-expansion
       balanced-match@1.0.2 /tmp/build_b3975c7b/node_modules/balanced-match
       concat-map@0.0.1 /tmp/build_b3975c7b/node_modules/concat-map
       path-is-absolute@1.0.1 /tmp/build_b3975c7b/node_modules/path-is-absolute
       graceful-fs@4.2.6 /tmp/build_b3975c7b/node_modules/graceful-fs
       handlebars@4.7.7 /tmp/build_b3975c7b/node_modules/handlebars
       minimist@1.2.5 /tmp/build_b3975c7b/node_modules/minimist
       neo-async@2.6.2 /tmp/build_b3975c7b/node_modules/neo-async
       source-map@0.6.1 /tmp/build_b3975c7b/node_modules/source-map
       wordwrap@1.0.0 /tmp/build_b3975c7b/node_modules/wordwrap
       @sindresorhus/is@0.14.0 /tmp/build_b3975c7b/node_modules/@sindresorhus/is
       @szmarczak/http-timer@1.1.2 /tmp/build_b3975c7b/node_modules/@szmarczak/http-timer
       defer-to-connect@1.1.3 /tmp/build_b3975c7b/node_modules/defer-to-connect
       abbrev@1.1.1 /tmp/build_b3975c7b/node_modules/abbrev
       ansi-regex@4.1.0 /tmp/build_b3975c7b/node_modules/ansi-regex
       ansi-styles@4.3.0 /tmp/build_b3975c7b/node_modules/ansi-styles
       color-convert@2.0.1 /tmp/build_b3975c7b/node_modules/color-convert
       color-name@1.1.4 /tmp/build_b3975c7b/node_modules/color-name
       anymatch@3.1.2 /tmp/build_b3975c7b/node_modules/anymatch
       normalize-path@3.0.0 /tmp/build_b3975c7b/node_modules/normalize-path
       picomatch@2.2.3 /tmp/build_b3975c7b/node_modules/picomatch
       binary-extensions@2.2.0 /tmp/build_b3975c7b/node_modules/binary-extensions
       boxen@4.2.0 /tmp/build_b3975c7b/node_modules/boxen
       ansi-align@3.0.0 /tmp/build_b3975c7b/node_modules/ansi-align
       string-width@3.1.0 /tmp/build_b3975c7b/node_modules/ansi-align/node_modules/string-width
       emoji-regex@7.0.3 /tmp/build_b3975c7b/node_modules/emoji-regex
       is-fullwidth-code-point@2.0.0 /tmp/build_b3975c7b/node_modules/is-fullwidth-code-point
       strip-ansi@5.2.0 /tmp/build_b3975c7b/node_modules/strip-ansi
       camelcase@5.3.1 /tmp/build_b3975c7b/node_modules/camelcase
       chalk@3.0.0 /tmp/build_b3975c7b/node_modules/chalk
       supports-color@7.2.0 /tmp/build_b3975c7b/node_modules/chalk/node_modules/supports-color
       has-flag@4.0.0 /tmp/build_b3975c7b/node_modules/chalk/node_modules/has-flag
       cli-boxes@2.2.1 /tmp/build_b3975c7b/node_modules/cli-boxes
       string-width@4.2.2 /tmp/build_b3975c7b/node_modules/string-width
       emoji-regex@8.0.0 /tmp/build_b3975c7b/node_modules/string-width/node_modules/emoji-regex
       is-fullwidth-code-point@3.0.0 /tmp/build_b3975c7b/node_modules/string-width/node_modules/is-fullwidth-code-point
       strip-ansi@6.0.0 /tmp/build_b3975c7b/node_modules/string-width/node_modules/strip-ansi
       ansi-regex@5.0.0 /tmp/build_b3975c7b/node_modules/string-width/node_modules/ansi-regex
       term-size@2.2.1 /tmp/build_b3975c7b/node_modules/term-size
       type-fest@0.8.1 /tmp/build_b3975c7b/node_modules/type-fest
       widest-line@3.1.0 /tmp/build_b3975c7b/node_modules/widest-line
       braces@3.0.2 /tmp/build_b3975c7b/node_modules/braces
       fill-range@7.0.1 /tmp/build_b3975c7b/node_modules/fill-range
       to-regex-range@5.0.1 /tmp/build_b3975c7b/node_modules/to-regex-range
       is-number@7.0.0 /tmp/build_b3975c7b/node_modules/is-number
       chokidar@3.5.1 /tmp/build_b3975c7b/node_modules/chokidar
       glob-parent@5.1.2 /tmp/build_b3975c7b/node_modules/glob-parent
       is-glob@4.0.1 /tmp/build_b3975c7b/node_modules/is-glob
       is-extglob@2.1.1 /tmp/build_b3975c7b/node_modules/is-extglob
       is-binary-path@2.1.0 /tmp/build_b3975c7b/node_modules/is-binary-path
       readdirp@3.5.0 /tmp/build_b3975c7b/node_modules/readdirp
       ci-info@2.0.0 /tmp/build_b3975c7b/node_modules/ci-info
       clone-response@1.0.2 /tmp/build_b3975c7b/node_modules/clone-response
       mimic-response@1.0.1 /tmp/build_b3975c7b/node_modules/mimic-response
       configstore@5.0.1 /tmp/build_b3975c7b/node_modules/configstore
       dot-prop@5.3.0 /tmp/build_b3975c7b/node_modules/dot-prop
       is-obj@2.0.0 /tmp/build_b3975c7b/node_modules/is-obj
       make-dir@3.1.0 /tmp/build_b3975c7b/node_modules/make-dir
       semver@6.3.0 /tmp/build_b3975c7b/node_modules/make-dir/node_modules/semver
       unique-string@2.0.0 /tmp/build_b3975c7b/node_modules/unique-string
       crypto-random-string@2.0.0 /tmp/build_b3975c7b/node_modules/crypto-random-string
       write-file-atomic@3.0.3 /tmp/build_b3975c7b/node_modules/write-file-atomic
       imurmurhash@0.1.4 /tmp/build_b3975c7b/node_modules/imurmurhash
       is-typedarray@1.0.0 /tmp/build_b3975c7b/node_modules/is-typedarray
       signal-exit@3.0.3 /tmp/build_b3975c7b/node_modules/signal-exit
       typedarray-to-buffer@3.1.5 /tmp/build_b3975c7b/node_modules/typedarray-to-buffer
       xdg-basedir@4.0.0 /tmp/build_b3975c7b/node_modules/xdg-basedir
       decompress-response@3.3.0 /tmp/build_b3975c7b/node_modules/decompress-response
       deep-extend@0.6.0 /tmp/build_b3975c7b/node_modules/deep-extend
       duplexer3@0.1.4 /tmp/build_b3975c7b/node_modules/duplexer3
       end-of-stream@1.4.4 /tmp/build_b3975c7b/node_modules/end-of-stream
       escape-goat@2.1.1 /tmp/build_b3975c7b/node_modules/escape-goat
       get-stream@4.1.0 /tmp/build_b3975c7b/node_modules/get-stream
       pump@3.0.0 /tmp/build_b3975c7b/node_modules/pump
       global-dirs@2.1.0 /tmp/build_b3975c7b/node_modules/global-dirs
       ini@1.3.7 /tmp/build_b3975c7b/node_modules/ini
       got@9.6.0 /tmp/build_b3975c7b/node_modules/got
       cacheable-request@6.1.0 /tmp/build_b3975c7b/node_modules/cacheable-request
       get-stream@5.2.0 /tmp/build_b3975c7b/node_modules/cacheable-request/node_modules/get-stream
       http-cache-semantics@4.1.0 /tmp/build_b3975c7b/node_modules/http-cache-semantics
       keyv@3.1.0 /tmp/build_b3975c7b/node_modules/keyv
       json-buffer@3.0.0 /tmp/build_b3975c7b/node_modules/json-buffer
       lowercase-keys@2.0.0 /tmp/build_b3975c7b/node_modules/cacheable-request/node_modules/lowercase-keys
       normalize-url@4.5.0 /tmp/build_b3975c7b/node_modules/normalize-url
       responselike@1.0.2 /tmp/build_b3975c7b/node_modules/responselike
       lowercase-keys@1.0.1 /tmp/build_b3975c7b/node_modules/lowercase-keys
       p-cancelable@1.1.0 /tmp/build_b3975c7b/node_modules/p-cancelable
       to-readable-stream@1.0.0 /tmp/build_b3975c7b/node_modules/to-readable-stream
       url-parse-lax@3.0.0 /tmp/build_b3975c7b/node_modules/url-parse-lax
       prepend-http@2.0.0 /tmp/build_b3975c7b/node_modules/prepend-http
       has-flag@3.0.0 /tmp/build_b3975c7b/node_modules/has-flag
       has-yarn@2.1.0 /tmp/build_b3975c7b/node_modules/has-yarn
       ignore-by-default@1.0.1 /tmp/build_b3975c7b/node_modules/ignore-by-default
       import-lazy@2.1.0 /tmp/build_b3975c7b/node_modules/import-lazy
       is-installed-globally@0.3.2 /tmp/build_b3975c7b/node_modules/is-installed-globally
       is-path-inside@3.0.3 /tmp/build_b3975c7b/node_modules/is-path-inside
       is-npm@4.0.0 /tmp/build_b3975c7b/node_modules/is-npm
       is-yarn-global@0.3.0 /tmp/build_b3975c7b/node_modules/is-yarn-global
       latest-version@5.1.0 /tmp/build_b3975c7b/node_modules/latest-version
       package-json@6.5.0 /tmp/build_b3975c7b/node_modules/package-json
       registry-auth-token@4.2.1 /tmp/build_b3975c7b/node_modules/registry-auth-token
       rc@1.2.8 /tmp/build_b3975c7b/node_modules/rc
       strip-json-comments@2.0.1 /tmp/build_b3975c7b/node_modules/strip-json-comments
       registry-url@5.1.0 /tmp/build_b3975c7b/node_modules/registry-url
       semver@6.3.0 /tmp/build_b3975c7b/node_modules/package-json/node_modules/semver
       pstree.remy@1.1.8 /tmp/build_b3975c7b/node_modules/pstree.remy
       pupa@2.1.1 /tmp/build_b3975c7b/node_modules/pupa
       supports-color@5.5.0 /tmp/build_b3975c7b/node_modules/supports-color
       undefsafe@2.0.3 /tmp/build_b3975c7b/node_modules/undefsafe
       update-notifier@4.1.3 /tmp/build_b3975c7b/node_modules/update-notifier
       is-ci@2.0.0 /tmp/build_b3975c7b/node_modules/is-ci
       semver-diff@3.1.1 /tmp/build_b3975c7b/node_modules/semver-diff
       semver@6.3.0 /tmp/build_b3975c7b/node_modules/semver-diff/node_modules/semver
       nopt@1.0.10 /tmp/build_b3975c7b/node_modules/nopt
       semver@5.7.1 /tmp/build_b3975c7b/node_modules/semver
       touch@3.1.0 /tmp/build_b3975c7b/node_modules/touch
       uglify-js@3.13.5 /tmp/build_b3975c7b/node_modules/uglify-js
       nodemon@2.0.7 /tmp/build_b3975c7b/node_modules/nodemon
       debug@3.2.7 /tmp/build_b3975c7b/node_modules/nodemon/node_modules/debug
       ms@2.1.3 /tmp/build_b3975c7b/node_modules/nodemon/node_modules/ms
       Installing any new modules (package.json)
       
       > node-sass@4.14.1 install /tmp/build_b3975c7b/node_modules/gulp-sass/node_modules/node-sass
       > node scripts/install.js
       
       Downloading binary from https://github.com/sass/node-sass/releases/download/v4.14.1/linux-x64-83_binding.node
       Download complete
       Binary saved to /tmp/build_b3975c7b/node_modules/gulp-sass/node_modules/node-sass/vendor/linux-x64-83/binding.node
       Caching binary to /tmp/npmcache.wd8xU/node-sass/4.14.1/linux-x64-83_binding.node
       
       > node-sass@5.0.0 install /tmp/build_b3975c7b/node_modules/node-sass
       > node scripts/install.js
       
       Downloading binary from https://github.com/sass/node-sass/releases/download/v5.0.0/linux-x64-83_binding.node
       Download complete
       Binary saved to /tmp/build_b3975c7b/node_modules/node-sass/vendor/linux-x64-83/binding.node
       Caching binary to /tmp/npmcache.wd8xU/node-sass/5.0.0/linux-x64-83_binding.node
       
       > highlight.js@9.18.5 postinstall /tmp/build_b3975c7b/node_modules/highlight.js
       > node deprecated.js
       
       -*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
       
         Verion 9 of Highlight.js has reached EOL.  It will no longer
         be supported or receive security updates in the future.
         Please upgrade to version 10 or encourage your indirect
         dependencies to do so.
       
         For more info:
         
         https://github.com/highlightjs/highlight.js/issues/2877
         https://github.com/highlightjs/highlight.js/blob/master/VERSION_10_UPGRADE.md
        
       -*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
       
       > node-sass@4.14.1 postinstall /tmp/build_b3975c7b/node_modules/gulp-sass/node_modules/node-sass
       > node scripts/build.js
       
       Binary found at /tmp/build_b3975c7b/node_modules/gulp-sass/node_modules/node-sass/vendor/linux-x64-83/binding.node
       Testing binary
       Binary is fine
       
       > node-sass@5.0.0 postinstall /tmp/build_b3975c7b/node_modules/node-sass
       > node scripts/build.js
       
       Binary found at /tmp/build_b3975c7b/node_modules/node-sass/vendor/linux-x64-83/binding.node
       Testing binary
       Binary is fine
       added 572 packages from 652 contributors and audited 751 packages in 17.707s
       
       22 packages are looking for funding
         run `npm fund` for details
       
       found 1 low severity vulnerability
         run `npm audit fix` to fix them, or `npm audit` for details
       
-----> Build
       
-----> Caching build
       - node_modules
       
-----> Pruning devDependencies
       removed 429 packages and audited 320 packages in 6.66s
       
       2 packages are looking for funding
         run `npm fund` for details
       
       found 0 vulnerabilities
       
       
-----> Build succeeded!