Improve error message in the absence of arguments to @b and add tes…

…ts (#153)

src/macro_tools.jl

@@ -75,23 +75,25 @@ function process_args(exprs)
     end
     primary_index = length(args) ÷ 2 + 2
     i = 3
-    while args[i] === :_ && i <= lastindex(args)
+    while i <= lastindex(args) && args[i] === :_
         args[i] = nothing
         i += 1
     end
-    if i == primary_index && args[i] isa Expr && args[i].head === :tuple
-        map!(create_first_function, args[i].args, args[i].args)
-    else
-        args[i] = create_first_function(args[i])
-    end
-    i += 1
-    while i <= lastindex(args)
+    if i <= lastindex(args)
         if i == primary_index && args[i] isa Expr && args[i].head === :tuple
-            map!(create_function, args[i].args, args[i].args)
+            map!(create_first_function, args[i].args, args[i].args)
         else
-            args[i] = create_function(args[i])
+            args[i] = create_first_function(args[i])
         end
         i += 1
+        while i <= lastindex(args)
+            if i == primary_index && args[i] isa Expr && args[i].head === :tuple
+                map!(create_function, args[i].args, args[i].args)
+            else
+                args[i] = create_function(args[i])
+            end
+            i += 1
+        end
     end
     call = exprarray(:call, args)
     esc(isempty(interpolations) ? call : Expr(:let, exprarray(:block, interpolations), Expr(:block, call)))

test/runtests.jl

@@ -73,6 +73,14 @@ else
             @test Chairmarks.only(b.samples).evals == 1
         end
 
+        @testset "process_args" begin
+            @test Chairmarks.process_args(()) == esc(:($(Chairmarks.benchmark)(;)))
+            @test Chairmarks.process_args((:(k=v),)) == esc(:($(Chairmarks.benchmark)(; k=v)))
+            @test Chairmarks.process_args((:(k=v), :(k=v2))) == esc(:($(Chairmarks.benchmark)(; k=v, k=v2)))
+            @test Chairmarks.process_args((:f,:(k=v))) == esc(:($(Chairmarks.benchmark)(f; k=v)))
+            @test_throws ErrorException("Positional argument after keyword argument") Chairmarks.process_args((:(k=v),:f))
+        end
+
         @testset "errors" begin
             @test_throws UndefKeywordError Sample(allocs=1.5, bytes=1729) # needs `time`
 
@@ -89,6 +97,14 @@ else
 
             t = @test_throws LoadError @eval(@b seconds=1 1+1)
             @test t.value.error == ErrorException("Positional argument after keyword argument")
+
+            #149
+            t = @test_throws MethodError @b # no arguments
+            @test t.value.f === Chairmarks.benchmark
+            @test t.value.args === ()
+
+            t = @test_throws ErrorException @eval(@b seconds=1 seconds=2)
+            @test startswith(t.value.msg, "syntax: keyword argument \"seconds\" repeated in call to \"")
         end
 
         @testset "time_ns() close to typemax(UInt64)" begin