Spacing around ternary operators, fixes #11.

src/Runic.jl

@@ -303,6 +303,7 @@ function format_node!(ctx::Context, node::Node)::Union{Node, Nothing, NullNode}
     @return_something spaces_around_operators(ctx, node)
     @return_something spaces_around_assignments(ctx, node)
     @return_something spaces_around_anonymous_function(ctx, node)
+    @return_something spaces_around_ternary(ctx, node)
     @return_something spaces_around_keywords(ctx, node)
     @return_something no_spaces_around_colon_etc(ctx, node)
     @return_something parens_around_op_calls_in_colon(ctx, node)

src/runestone.jl

@@ -682,6 +682,14 @@ function spaces_around_anonymous_function(ctx::Context, node::Node)
     return spaces_around_x(ctx, node, is_x)
 end
 
+function spaces_around_ternary(ctx::Context, node::Node)
+    if !(kind(node) === K"?" && !is_leaf(node))
+        return nothing
+    end
+    is_x = x -> is_leaf(x) && kind(x) in KSet"? :"
+    return spaces_around_x(ctx, node, is_x)
+end
+
 # Opposite of `spaces_around_x`: remove spaces around `x`
 function no_spaces_around_x(ctx::Context, node::Node, is_x::F) where {F}
     @assert !is_leaf(node)

test/runtests.jl

@@ -277,6 +277,17 @@ end
     end
 end
 
+@testset "whitespace around ternary" begin
+    for sp in (" ", "  ")
+        @test format_string("a$(sp)?$(sp)b$(sp):$(sp)c") == "a ? b : c"
+        @test format_string("a$(sp)?\nb$(sp):\nc") == "a ?\n    b :\n    c"
+        @test format_string("a$(sp)?$(sp)b$(sp):$(sp)c$(sp)?$(sp)d$(sp):$(sp)e") ==
+            "a ? b : c ? d : e"
+        @test format_string("a$(sp)?\nb$(sp):\nc$(sp)?\nd$(sp):\ne") ==
+            "a ?\n    b :\n    c ?\n    d :\n    e"
+    end
+end
+
 @testset "whitespace in comparison chains" begin
     for sp in ("", " ", "  ")
         @test format_string("a$(sp)==$(sp)b") == "a == b"