Allow expanding all short function definitions (#861)

* add max_short_function_length

* bump

* add show method for Options

* add force_long_function_def

* document force_long_function_def

* set version

---------

Co-authored-by: Dominique Luna <dluna132@gmail.com>

Project.toml

@@ -1,7 +1,7 @@
 name = "JuliaFormatter"
 uuid = "98e50ef6-434e-11e9-1051-2b60c6c9e899"
 authors = ["Dominique Luna <dluna132@gmail.com>"]
-version = "1.0.59"
+version = "1.0.60"
 
 [deps]
 CSTParser = "00ebfdb7-1f24-5e51-bd34-a7502290713f"

docs/src/index.md

@@ -176,14 +176,21 @@ Transforms a *short* function definition
 f(arg1, arg2) = body
 ```
 
-to a *long* function definition if the short function definition exceeds the maximum margin.
+to a *long* function definition if the short function definition exceeds the maximum margin. Or
+if `force_long_function_def` is set to `true`.
 
 ```julia
 function f(arg2, arg2)
     body
 end
 ```
 
+### `force_long_function_def`
+> default: `false`
+
+If `true` tweaks the behavior of `short_to_long_function_def` to force the transformation no matter 
+how short the function definition is.
+
 ### `long_to_short_function_def`
 
 > default: `false`

src/options.jl

@@ -12,6 +12,7 @@ Base.@kwdef struct Options
     pipe_to_function_call::Bool = false
     short_to_long_function_def::Bool = false
     long_to_short_function_def::Bool = false
+    force_long_function_def::Bool = false
     always_use_return::Bool = false
     whitespace_in_kwargs::Bool = true
     annotate_untyped_fields_with_any::Bool = true
@@ -35,6 +36,22 @@ Base.@kwdef struct Options
     yas_style_nesting::Bool = false
     short_circuit_to_if::Bool = false
     disallow_single_arg_nesting::Bool = false
+    function Options(args...)
+        opts = new(args...)
+        if (opts.force_long_function_def === true) &&
+           (opts.short_to_long_function_def === false)
+            msg = """
+            The combination `force_long_function_def = true` and `short_to_long_function_def = false` is invalid.
+            """
+            throw(ArgumentError(msg))
+        end
+        return opts
+    end
+end
+
+function Base.show(io::IO, opt::Options)
+    print(io, "Options")
+    print(io, NamedTuple(key => getproperty(opt, key) for key in fieldnames(Options)))
 end
 
 function needs_alignment(opts::Options)

src/styles/default/nest.jl

@@ -82,7 +82,7 @@ function nest!(ds::DefaultStyle, fst::FST, s::State)
     elseif fst.typ === Binary
         line_margin = s.line_offset + length(fst) + fst.extra_margin
         if s.opts.short_to_long_function_def &&
-           line_margin > s.opts.margin &&
+           ((line_margin > s.opts.margin) || s.opts.force_long_function_def) &&
            fst.ref !== nothing &&
            CSTParser.defines_function(fst.ref[]) &&
            !parent_is(fst.ref[], n -> n.head == :let)

test/options.jl

@@ -299,6 +299,20 @@
             bodybodybodybodybodybodybody
         end"""
         @test fmt(str_, 4, length(str_), short_to_long_function_def = true) == str_
+        @test fmt(
+            str_,
+            4,
+            length(str_),
+            short_to_long_function_def = true,
+            force_long_function_def = true,
+        ) == str
+        @test fmt(
+            str_,
+            4,
+            length(str_),
+            short_to_long_function_def = false,
+            force_long_function_def = false,
+        ) == str_
         @test fmt(str_, 4, length(str_) - 1, short_to_long_function_def = true) == str
     end