Add missing tab-completion help for emoji (#34034)

* Add missing tab-completion help for emoji

Closes: #34006

* Add tests for tab-completion on emoji

* Drop Base.REPL_MODULE_REF[] as it is a part of REPL

* Use colons

Signed-off-by: Utkarsh Gupta <[email protected]>

* Update docview.jl

* fix test

Co-authored-by: Steven G. Johnson <[email protected]>
Co-authored-by: Steven G. Johnson <[email protected]>

Author: utkarsh2102

stdlib/REPL/src/docview.jl

@@ -11,6 +11,8 @@ import Base.Docs: doc, formatdoc, parsedoc, apropos
 
 using Base: with_output_color
 
+import REPL
+
 using InteractiveUtils: subtypes
 
 using Unicode: normalize
@@ -323,7 +325,8 @@ repl_corrections(s) = repl_corrections(stdout, s)
 const symbols_latex = Dict{String,String}()
 function symbol_latex(s::String)
     if isempty(symbols_latex) && isassigned(Base.REPL_MODULE_REF)
-        for (k,v) in Base.REPL_MODULE_REF[].REPLCompletions.latex_symbols
+        for (k,v) in Iterators.flatten((REPLCompletions.latex_symbols,
+                                        REPLCompletions.emoji_symbols))
             symbols_latex[v] = k
         end
     end

stdlib/REPL/test/docview.jl

@@ -0,0 +1,16 @@
+# This file is a part of Julia. License is MIT: https://julialang.org/license
+
+using Test
+import REPL
+
+@testset "symbol completion" begin
+    @test startswith(let buf = IOBuffer()
+            Core.eval(Main, REPL.helpmode(buf, "α"))
+            String(take!(buf))
+        end, "\"α\" can be typed by \\alpha<tab>\n")
+
+    @test startswith(let buf = IOBuffer()
+            Core.eval(Main, REPL.helpmode(buf, "🐨"))
+            String(take!(buf))
+        end, "\"🐨\" can be typed by \\:koala:<tab>\n")
+end

stdlib/REPL/test/runtests.jl

@@ -9,6 +9,9 @@ end
 module LineEditTest
     include("lineedit.jl")
 end
+module DocviewTest
+    include("docview.jl")
+end
 module TerminalMenusTest
     include("TerminalMenus/runtests.jl")
 end