[REPL] Fix keyword arguments completions with do block (#59123)

In `_complete_methods`, desugar the `:do` Expr into a call with a lambda
in the first argument.

Fixes #58833.

(cherry picked from commit 50c8956)

Author: xal-0

stdlib/REPL/src/REPLCompletions.jl

@@ -698,6 +698,15 @@ code_typed(CC.typeinf, (REPLInterpreter, CC.InferenceState))
 MAX_METHOD_COMPLETIONS::Int = 40
 function _complete_methods(ex_org::Expr, context_module::Module, shift::Bool)
     isempty(ex_org.args) && return 2, nothing, [], Set{Symbol}()
+    # Desugar do block call into call with lambda
+    if ex_org.head === :do && length(ex_org.args) >= 2
+        ex_call = ex_org.args[1]
+        ex_args = [x for x in ex_call.args if !(x isa Expr && x.head === :parameters)]
+        ex_params = findfirst(x -> x isa Expr && x.head === :parameters, ex_call.args)
+        new_args = [ex_args[1], ex_org.args[end], ex_args[2:end]...]
+        ex_params !== nothing && push!(new_args, ex_call.args[ex_params])
+        ex_org = Expr(:call, new_args...)
+    end
     funct = repl_eval_ex(ex_org.args[1], context_module)
     funct === nothing && return 2, nothing, [], Set{Symbol}()
     funct = CC.widenconst(funct)

stdlib/REPL/test/replcompletions.jl

@@ -139,6 +139,7 @@ let ex =
             kwtest4(a::SubString; x23, _something) = pass
             kwtest5(a::Int, b, x...; somekwarg, somekotherkwarg) = pass
             kwtest5(a::Char, b; xyz) = pass
+            kwtest6(f::Function, arg1; somekwarg) = pass
 
             const named = (; len2=3)
             const fmsoebelkv = (; len2=3)
@@ -198,6 +199,8 @@ test_scomplete(s) =  map_completion_text(@inferred(shell_completions(s, lastinde
 test_complete_pos(s) = map_completion_text(@inferred(completions(replace(s, '|' => ""), findfirst('|', s)-1)))
 test_complete_context(s, m=@__MODULE__; shift::Bool=true) =
     map_completion_text(@inferred(completions(s,lastindex(s), m, shift)))
+test_complete_context_pos(s, m=@__MODULE__; shift::Bool=true) =
+    map_completion_text(@inferred(completions(replace(s, '|' => ""), findfirst('|', s)-1, m, shift)))
 test_complete_foo(s; shift::Bool=true) = test_complete_context(s, Main.CompletionFoo; shift)
 test_complete_noshift(s) = map_completion_text(@inferred(completions(s, lastindex(s), Main, false)))
 
@@ -2720,3 +2723,10 @@ let s = "foo58296(findfi"
     @test "findfirst" in c
     @test r == 10:15
 end
+
+# #58833 - Autocompletion of keyword arguments with do-blocks is broken
+let s = "kwtest6(123; som|) do x; x + 3 end"
+    c, r = test_complete_context_pos(s, Main.CompletionFoo)
+    @test "somekwarg=" in c
+    @test r == 14:16
+end