Fix space-around-operator with non-space whitespace

src/runestone.jl

@@ -189,9 +189,7 @@ function spaces_around_x(ctx::Context, node::Node, is_x::F, n_leaves_per_x::Int
                     # Replace the whitespace node of the kid
                     kid′ = replace_first_leaf(kid, ws)
                     @assert span(kid′) == span(kid) - span(kid_ws) + 1
-                    bytes_to_skip = span(kid) - span(kid′)
+                    replace_bytes!(ctx, " ", span(kid_ws))
-                    @assert bytes_to_skip > 0
-                    replace_bytes!(ctx, "", bytes_to_skip)
                     accept_node!(ctx, kid′)
                     any_changes = true
                     if kids′ === kids

test/runtests.jl

@@ -384,6 +384,9 @@ end
     @test format_string("(\na, x -> @m(x[i])\n)") == "(\n    a, x -> @m(x[i]),\n)"
     # Weird cornercase where a trailing comma messes some cases up (don't recall...)
     @test format_string("{\n@f\n}") == "{\n    @f\n}"
+    # Non space whitespace (TODO: Not sure if a JuliaSyntax bug or not?)
+    @test format_string(String(UInt8[0x61, 0x20, 0x3d, 0x3d, 0x20, 0xc2, 0xa0, 0x62, 0x3a, 0x63])) ==
+        "a == b:c"
 end
 
 @testset "whitespace around ->" begin