This adds a 404 page

I personally prefer a wide banner just like GitHub in https://github.com/ghost/dummy ,
but this is good enough to have as a placeholder, feel free to overwrite me with a design.

server/fishtest/templates/notfound.mak

@@ -0,0 +1,51 @@
+<%inherit file="base.mak"/>
+
+<script>
+  document.title = "Page not found";
+</script>
+
+<style>
+  .error-container {
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    height: 82vh;
+  }
+  .error-content {
+    text-align: center;
+  }
+  .error-heading {
+    font-size: 6rem;
+    color: #343a40;
+    margin-bottom: 1rem;
+  }
+  .error-message {
+    font-size: 1.5rem;
+    color: #6c757d;
+    margin-bottom: 2rem;
+  }
+  .error-button {
+    display: inline-block;
+    padding: 0.75rem 1.5rem;
+    background-color: #77828f;
+    color: #fff;
+    text-decoration: none;
+    border-radius: 5px;
+    transition: background-color 0.3s;
+    border: none;
+    cursor: pointer;
+    outline: none;
+  }
+  .error-button:hover {
+    background-color: #0056b3;
+  }
+</style>
+
+<div class="error-container">
+  <div class="error-content">
+    <h1 class="error-heading">404</h1>
+    <h2 class="error-message">Oops! Page not found.</h2>
+    <p class="lead">The page you are looking for might have been removed, had its name changed, or is temporarily unavailable.</p>
+    <a href="/" class="error-button">Go to Home</a>
+  </div>
+</div>

server/fishtest/views.py

@@ -23,9 +23,9 @@
     password_strength,
     update_residuals,
 )
-from pyramid.httpexceptions import HTTPFound, exception_response
+from pyramid.httpexceptions import HTTPFound, HTTPNotFound, exception_response
 from pyramid.security import forget, remember
-from pyramid.view import forbidden_view_config, view_config
+from pyramid.view import forbidden_view_config, notfound_view_config, view_config
 from requests.exceptions import ConnectionError, HTTPError
 from vtjson import ValidationError, union, validate
 
@@ -81,6 +81,12 @@ def pagination(page_idx, num, page_size, query_params):
     return pages
 
 
+@notfound_view_config(renderer="notfound.mak")
+def notfound_view(request):
+    request.response.status = 404
+    return {}
+
+
 @view_config(route_name="home")
 def home(request):
     return HTTPFound(location=request.route_url("tests"))
@@ -585,7 +591,7 @@ def user(request):
 
     user_data = request.userdb.get_user(user_name)
     if user_data is None:
-        raise exception_response(404)
+        raise HTTPNotFound("Resource not found")
     if "user" in request.POST:
         if profile:
             old_password = request.params.get("old_password").strip()
@@ -1175,7 +1181,7 @@ def tests_run(request):
     if "id" in request.params:
         run = request.rundb.get_run(request.params["id"])
         if run is None:
-            raise exception_response(404)
+            raise HTTPNotFound("Resource not found")
         run_args = copy.deepcopy(run["args"])
         if "spsa" in run_args:
             # needs deepcopy
@@ -1405,23 +1411,23 @@ def get_page_title(run):
 def tests_live_elo(request):
     run = request.rundb.get_run(request.matchdict["id"])
     if run is None:
-        raise exception_response(404)
+        raise HTTPNotFound("Resource not found")
     return {"run": run, "page_title": get_page_title(run)}
 
 
 @view_config(route_name="tests_stats", renderer="tests_stats.mak")
 def tests_stats(request):
     run = request.rundb.get_run(request.matchdict["id"])
     if run is None:
-        raise exception_response(404)
+        raise HTTPNotFound("Resource not found")
     return {"run": run, "page_title": get_page_title(run)}
 
 
 @view_config(route_name="tests_tasks", renderer="tasks.mak")
 def tests_tasks(request):
     run = request.rundb.get_run(request.matchdict["id"])
     if run is None:
-        raise exception_response(404)
+        raise HTTPNotFound("Resource not found")
 
     try:
         show_task = int(request.params.get("show_task", -1))
@@ -1446,7 +1452,7 @@ def tests_machines(request):
 def tests_view(request):
     run = request.rundb.get_run(request.matchdict["id"])
     if run is None:
-        raise exception_response(404)
+        raise HTTPNotFound("Resource not found")
     follow = 1 if "follow" in request.params else 0
     results = run["results"]
     run["results_info"] = format_results(results, run)
@@ -1652,6 +1658,9 @@ def tests_user(request):
         )
     )
     username = request.matchdict.get("username", "")
+    user_data = request.userdb.get_user(username)
+    if user_data is None:
+        raise HTTPNotFound("Resource not found")
     response = {**get_paginated_finished_runs(request), "username": username}
     page_param = request.params.get("page", "")
     if not page_param.isdigit() or int(page_param) <= 1: