throw error in trixi_include when assignment is not found

Author: JoshuaLampert

src/util.jl

@@ -96,6 +96,16 @@ julia> redirect_stdout(devnull) do
 ```
 """
 function trixi_include(mod::Module, example::AbstractString; kwargs...)
+    # Check that all kwargs exist as assignments
+    code = read(example, String)
+    expr = Meta.parse("begin \n$code \nend")
+    expr = insert_maxiters(expr)
+
+    for (key, val) in kwargs
+        # This will throw an error when `key` is not found
+        find_assignment(expr, key)
+    end
+
     Base.include(ex -> replace_assignments(insert_maxiters(ex); kwargs...), mod, example)
 end
 
@@ -282,19 +292,25 @@ end
 function find_assignment(expr, destination)
     # declare result to be able to assign to it in the closure
     local result
+    found = false
 
     # find explicit and keyword assignments
     walkexpr(expr) do x
         if x isa Expr
             if (x.head === Symbol("=") || x.head === :kw) &&
                x.args[1] === Symbol(destination)
                 result = x.args[2]
+                found = true
                 # dump(x)
             end
         end
         return x
     end
 
+    if !found
+        throw(ArgumentError("assignment `$destination` not found in expression"))
+    end
+
     result
 end