Fix commas after trailing macrocalls hidden inside of list items (#67)

src/chisels.jl

@@ -630,6 +630,20 @@ function last_leaf_predicate(node::Node, pred::F) where {F}
     end
 end
 
+function predicate_contains(pred::F, node::Node) where {F}
+    if pred(node)::Bool
+        return true
+    elseif is_leaf(node)
+        return false
+    else
+        for k in verified_kids(node)
+            r = predicate_contains(pred, k)
+            r && return r
+        end
+        return false
+    end
+end
+
 function contains_outer_newline(kids::Vector{Node}, oidx::Int, cidx::Int; recurse = true)
     pred = x -> kind(x) === K"NewlineWs" || !JuliaSyntax.is_whitespace(x)
     for i in (oidx + 1):(cidx - 1)

src/runestone.jl

@@ -387,9 +387,11 @@ function spaces_in_listlike(ctx::Context, node::Node)
         # For parameters the trailing comma is configured from the parent
         require_trailing_comma = has_tag(node, TAG_TRAILING_COMMA)
         allow_trailing_comma = has_tag(node, TAG_TRAILING_COMMA_OPT)
-    elseif n_items > 0 && kind(kids[last_item_idx]) === K"macrocall" &&
+    elseif n_items > 0 && predicate_contains(kids[last_item_idx]) do nd
-            !JuliaSyntax.has_flags(kids[last_item_idx], JuliaSyntax.PARENS_FLAG) &&
+            return kind(nd) === K"macrocall" &&
-            !is_string_macro(kids[last_item_idx])
+                !JuliaSyntax.has_flags(nd, JuliaSyntax.PARENS_FLAG) && !is_string_macro(nd)
+        end
+        # Unparenthesized macrocalls are scary even if hidden deep in the tree
         require_trailing_comma = false
     elseif multiline
         require_trailing_comma = true

test/runtests.jl

@@ -379,6 +379,9 @@ end
     @test format_string("f(r\"\"\"\nf\n\"\"\")") == "f(\n    r\"\"\"\n    f\n    \"\"\"\n)"
     @test format_string("f(```\nf\n```)") == "f(\n    ```\n    f\n    ```\n)"
     @test format_string("f(x```\nf\n```)") == "f(\n    x```\n    f\n    ```\n)"
+    @test format_string("(a, @m begin\nend)") == "(\n    a, @m begin\n    end\n)"
+    @test format_string("(\na, x -> @m x[i]\n)") == "(\n    a, x -> @m x[i]\n)"
+    @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}"
 end