Refactor shell completion into a separate module (#281)

- Adds cc.completions module, with a couple of helper functions for
   working with the more general completion functionality (i.e. that
   provided by read).
 - Adds cc.shell.completions module, which provides shell-specific
   completion functions.
 - Add a "program completion builder", which allows you to write stuff
   like this:

       shell.setCompletionFunction( "rom/programs/redstone.lua", 
         completion.build(
           { completion.choice, { "probe", "set ", "pulse " } },
           completion.side) )

Closes #232

src/main/resources/assets/computercraft/lua/rom/modules/main/cc/completion.lua

@@ -0,0 +1,105 @@
+--- A collection of helper methods for working with input completion, such
+-- as that require by @{read}.
+--
+-- @module craftos.completion
+-- @see cc.shell.completion For additional helpers to use with
+-- @{shell.setCompletionFunction}.
+
+local expect = require "cc.expect".expect
+
+local function choice_impl(text, choices, add_space)
+    local results = {}
+    for n = 1, #choices do
+        local option = choices[n]
+        if #option + (add_space and 1 or 0) > #text and option:sub(1, #text) == text then
+            local result = option:sub(#text + 1)
+            if add_space then
+                table.insert(results, result .. " ")
+            else
+                table.insert(results, result)
+            end
+        end
+    end
+    return results
+end
+
+--- Complete from a choice of one or more strings.
+--
+-- @tparam string text The input string to complete.
+-- @tparam { string... } choices The list of choices to complete from.
+-- @tparam[opt] boolean add_space Whether to add a space after the completed item.
+-- @treturn { string... } A list of suffixes of matching strings.
+-- @usage Call @{read}, completing the names of various animals.
+--
+--     local animals = { "dog", "cat", "lion", "unicorn" }
+--     read(nil, nil, function(text) return choice(text, animals) end)
+local function choice(text, choices, add_space)
+    expect(1, text, "string")
+    expect(2, choices, "table")
+    expect(3, add_space, "boolean", "nil")
+    return choice_impl(text, choices, add_space)
+end
+
+--- Complete the name of a currently attached peripheral.
+--
+-- @tparam string text The input string to complete.
+-- @tparam[opt] boolean add_space Whether to add a space after the completed name.
+-- @treturn { string... } A list of suffixes of matching peripherals.
+-- @usage read(nil, nil, peripheral)
+local function peripheral_(text, add_space)
+    expect(1, text, "string")
+    expect(2, add_space, "boolean", "nil")
+    return choice_impl(text, peripheral.getNames(), add_space)
+end
+
+local sides = redstone.getSides()
+
+--- Complete the side of a computer.
+--
+-- @tparam string text The input string to complete.
+-- @tparam[opt] boolean add_space Whether to add a space after the completed side.
+-- @treturn { string... } A list of suffixes of matching sides.
+-- @usage read(nil, nil, side)
+local function side(text, add_space)
+    expect(1, text, "string")
+    expect(2, add_space, "boolean", "nil")
+    return choice_impl(text, sides, add_space)
+end
+
+--- Complete a @{settings|setting}.
+--
+-- @tparam string text The input string to complete.
+-- @tparam[opt] boolean add_space Whether to add a space after the completed settings.
+-- @treturn { string... } A list of suffixes of matching settings.
+-- @usage read(nil, nil, setting)
+local function setting(text, add_space)
+    expect(1, text, "string")
+    expect(2, add_space, "boolean", "nil")
+    return choice_impl(text, settings.getNames(), add_space)
+end
+
+local command_list
+
+--- Complete the name of a Minecraft @{commands|command}.
+--
+-- @tparam string text The input string to complete.
+-- @tparam[opt] boolean add_space Whether to add a space after the completed command.
+-- @treturn { string... } A list of suffixes of matching commands.
+-- @usage read(nil, nil, command)
+local function command(text, add_space)
+    expect(1, text, "string")
+    expect(2, add_space, "boolean", "nil")
+    if command_list == nil then
+        command_list = commands and commands.list() or {}
+    end
+
+    return choice_impl(text, command_list, add_space)
+end
+
+return {
+    choice = choice,
+    peripheral = peripheral_,
+    side = side,
+    setting = setting,
+    command = command,
+}

src/main/resources/assets/computercraft/lua/rom/modules/main/cc/shell/completion.lua

@@ -0,0 +1,151 @@
+--- A collection of helper methods for working with shell completion.
+--
+-- Most programs may be completed using the @{build} helper method, rather than
+-- manually switching on the argument index.
+--
+-- Note, the helper functions within this module do not accept an argument index,
+-- and so are not directly usable with the @{shell.setCompletionFunction}. Instead,
+-- wrap them using @{build}, or your own custom function.
+--
+-- @module craftos.shell.completion
+-- @see cc.completion For more general helpers, suitable for use with @{read}.
+-- @see shell.setCompletionFunction
+
+local expect = require "cc.expect".expect
+local completion = require "cc.completion"
+
+--- Complete the name of a file relative to the current working directory.
+--
+-- @tparam shell shell The shell we're completing in
+-- @tparam { string... } choices The list of choices to complete from.
+-- @treturn { string... } A list of suffixes of matching files.
+local function file(shell, text)
+    return fs.complete(text, shell.dir(), true, false)
+end
+
+--- Complete the name of a directory relative to the current working directory.
+--
+-- @tparam shell shell The shell we're completing in
+-- @tparam { string... } choices The list of choices to complete from.
+-- @treturn { string... } A list of suffixes of matching directories.
+local function dir(shell, text)
+    return fs.complete(text, shell.dir(), false, true)
+end
+
+--- Complete the name of a file or directory relative to the current working
+-- directory.
+--
+-- @tparam shell shell The shell we're completing in
+-- @tparam { string... } choices The list of choices to complete from.
+-- @tparam { string... } previous The shell arguments before this one.
+-- @tparam[opt] boolean add_space Whether to add a space after the completed item.
+-- @treturn { string... } A list of suffixes of matching files and directories.
+local function dirOrFile(shell, text, previous, add_space)
+    local results = fs.complete(text, shell.dir(), true, true)
+    if add_space then
+        for n = 1, #results do
+            local result = results[n]
+            if result:sub(-1) ~= "/" then
+                results[n] = result .. " "
+            end
+        end
+    end
+    return results
+end
+
+local function wrap(func)
+    return function(shell, text, previous, ...)
+        return func(text, ...)
+    end
+end
+
+--- Complete the name of a program.
+--
+-- @tparam shell shell The shell we're completing in
+-- @tparam { string... } choices The list of choices to complete from.
+-- @treturn { string... } A list of suffixes of matching programs.
+local function program(shell, text)
+    return shell.completeProgram(text)
+end
+
+--- A helper function for building shell completion arguments.
+--
+-- This accepts a series of single-argument completion functions, and combines
+-- them into a function suitable for use with @{shell.setCompletionFunction}.
+--
+-- @tparam nil|table|function ... Every argument to @{build} represents an argument
+-- to the program you wish to complete. Each argument can be one of three types:
+--
+--  - `nil`: This argument will not be completed.
+--
+--  - A function: This argument will be completed with the given function. It is
+--    called with the @{shell} object, the string to complete and the arguments
+--    before this one.
+--
+--  - A table: This acts as a more powerful version of the function case. The table
+--    must have a function as the first item - this will be called with the shell,
+--    string and preceding arguments as above, but also followed by any additional
+--    items in the table. This provides a more convenient interface to pass
+--    options to your completion functions.
+--
+--    If this table is the last argument, it may also set the `many` key to true,
+--    which states this function should be used to complete any remaining arguments.
+--
+-- @usage Prompt for a choice of options, followed by a directory, and then multiple
+-- files.
+--
+--     complete.build(
+--       { complete.choice, { "get", "put" } },
+--       complete.dir,
+--       } complete.file, many = true }
+--     )
+local function build(...)
+    local arguments = table.pack(...)
+    for i = 1, arguments.n do
+        local arg = arguments[i]
+        if arg ~= nil then
+            expect(i, arg, "table", "function")
+            if type(arg) == "function" then
+                arg = { arg }
+                arguments[i] = arg
+            end
+
+            if type(arg[1]) ~= "function" then
+                error(("Bad table entry #1 at argument #%d (expected function, got %s)"):format(i, type(arg[1])), 2)
+            end
+
+            if arg.many and i < arguments.n then
+                error(("Unexpected 'many' field on argument #%d (should only occur on the last argument)"):format(i), 2)
+            end
+        end
+    end
+
+    return function(shell, index, text, previous)
+        local arg = arguments[index]
+        if not arg then
+            if index <= arguments.n then return end
+
+            arg = arguments[arguments.n]
+            if not arg or not arg.many then return end
+        end
+
+        return arg[1](shell, text, previous, table.unpack(arg, 2))
+    end
+end
+
+return {
+    file = file,
+    dir = dir,
+    dirOrFile = dirOrFile,
+    program = program,
+
+    -- Re-export various other functions
+    help = wrap(help.completeTopic),
+    choice = wrap(completion.choice),
+    peripheral = wrap(completion.peripheral),
+    side = wrap(completion.side),
+    setting = wrap(completion.setting),
+    command = wrap(completion.command),
+
+    build = build,
+}

src/main/resources/assets/computercraft/lua/rom/startup.lua

@@ -1,3 +1,4 @@
+local completion = require "cc.shell.completion"
 
 -- Setup paths
 local sPath = ".:/rom/programs"
@@ -39,217 +40,86 @@ if term.isColor() then
 end
 
 -- Setup completion functions
-local function completeMultipleChoice( sText, tOptions, bAddSpaces )
+
-    local tResults = {}
+local function completePastebinPut(shell, text, previous)
-    for n=1,#tOptions do
+    if previous[2] == "put" then
-        local sOption = tOptions[n]
+        return fs.complete(text, shell.dir(), true, false )
-        if #sOption + (bAddSpaces and 1 or 0) > #sText and string.sub( sOption, 1, #sText ) == sText then
-            local sResult = string.sub( sOption, #sText + 1 )
-            if bAddSpaces then
-                table.insert( tResults, sResult .. " " )
-            else
-                table.insert( tResults, sResult )
     end
 end
-    end
+
-    return tResults
+shell.setCompletionFunction( "rom/programs/alias.lua", completion.build(nil, completion.program) )
-end
+shell.setCompletionFunction( "rom/programs/cd.lua", completion.build(completion.dir) )
-local function completePeripheralName( sText, bAddSpaces )
+shell.setCompletionFunction( "rom/programs/copy.lua", completion.build(
-    return completeMultipleChoice( sText, peripheral.getNames(), bAddSpaces )
+    { completion.dirOrFile, true },
-end
+    completion.dirOrFile
-local tRedstoneSides = redstone.getSides()
+) )
-local function completeSide( sText, bAddSpaces )
+shell.setCompletionFunction( "rom/programs/delete.lua", completion.build({ completion.dirOrFile, many = true }) )
-    return completeMultipleChoice( sText, tRedstoneSides, bAddSpaces )
+shell.setCompletionFunction( "rom/programs/drive.lua", completion.build(completion.dir) )
-end
+shell.setCompletionFunction( "rom/programs/edit.lua", completion.build(completion.file) )
-local function completeFile( shell, nIndex, sText, tPreviousText )
+shell.setCompletionFunction( "rom/programs/eject.lua", completion.build(completion.peripheral) )
-    if nIndex == 1 then
+shell.setCompletionFunction( "rom/programs/gps.lua", completion.build({ completion.choice, { "host", "host ", "locate" } }) )
-        return fs.complete( sText, shell.dir(), true, false )
+shell.setCompletionFunction( "rom/programs/help.lua", completion.build(completion.help) )
-    end
+shell.setCompletionFunction( "rom/programs/id.lua", completion.build(completion.peripheral) )
-end
+shell.setCompletionFunction( "rom/programs/label.lua", completion.build(
-local function completeFileMany( shell, nIndex, sText, tPreviousText )
+    { completion.choice, { "get", "get ", "set ", "clear", "clear " } },
-    return fs.complete( sText, shell.dir(), true, false )
+    completion.peripheral
-end
+) )
-local function completeDir( shell, nIndex, sText, tPreviousText )
+shell.setCompletionFunction( "rom/programs/list.lua", completion.build(completion.dir) )
-    if nIndex == 1 then
+shell.setCompletionFunction( "rom/programs/mkdir.lua", completion.build({ completion.dir, many = true }) )
-        return fs.complete( sText, shell.dir(), false, true )
+shell.setCompletionFunction( "rom/programs/monitor.lua", completion.build(
-    end
+    { completion.peripheral, true },
-end
+    completion.program
-local function completeEither( shell, nIndex, sText, tPreviousText )
+) )
-    if nIndex == 1 then
+shell.setCompletionFunction( "rom/programs/move.lua", completion.build(
-        return fs.complete( sText, shell.dir(), true, true )
+    { completion.dirOrFile, true },
-    end
+    completion.dirOrFile
-end
+) )
-local function completeEitherMany( shell, nIndex, sText, tPreviousText )
+shell.setCompletionFunction( "rom/programs/redstone.lua", completion.build(
-    return fs.complete( sText, shell.dir(), true, true )
+    { completion.choice, { "probe", "set ", "pulse " } },
-end
+    completion.side
-local function completeEitherEither( shell, nIndex, sText, tPreviousText )
+) )
-    if nIndex == 1 then
+shell.setCompletionFunction( "rom/programs/rename.lua", completion.build(
-        local tResults = fs.complete( sText, shell.dir(), true, true )
+    { completion.dirOrFile, true },
-        for n=1,#tResults do
+    completion.dirOrFile
-            local sResult = tResults[n]
+) )
-            if string.sub( sResult, #sResult, #sResult ) ~= "/" then
+shell.setCompletionFunction( "rom/programs/shell.lua", completion.build(completion.program) )
-                tResults[n] = sResult .. " "
+shell.setCompletionFunction( "rom/programs/type.lua", completion.build(completion.dirOrFile) )
-            end
+shell.setCompletionFunction( "rom/programs/set.lua", completion.build({ completion.setting, true }) )
-        end
+shell.setCompletionFunction( "rom/programs/advanced/bg.lua", completion.build(completion.program) )
-        return tResults
+shell.setCompletionFunction( "rom/programs/advanced/fg.lua", completion.build(completion.program) )
-    elseif nIndex == 2 then
+shell.setCompletionFunction( "rom/programs/fun/dj.lua", completion.build(
-        return fs.complete( sText, shell.dir(), true, true )
+    { completion.choice, { "play", "play ", "stop " } },
-    end
+    completion.peripheral
-end
+) )
-local function completeProgram( shell, nIndex, sText, tPreviousText )
+shell.setCompletionFunction( "rom/programs/fun/advanced/paint.lua", completion.build(completion.file) )
-    if nIndex == 1 then
+shell.setCompletionFunction( "rom/programs/http/pastebin.lua", completion.build(
-        return shell.completeProgram( sText )
+    { completion.choice, { "put ", "get ", "run " } },
-    end
+    completePastebinPut
-end
+) )
-local function completeHelp( shell, nIndex, sText, tPreviousText )
+shell.setCompletionFunction( "rom/programs/rednet/chat.lua", completion.build({ completion.choice, { "host ", "join " } }) )
-    if nIndex == 1 then
+shell.setCompletionFunction( "rom/programs/command/exec.lua", completion.build(completion.command) )
-        return help.completeTopic( sText )
+shell.setCompletionFunction( "rom/programs/http/wget.lua", completion.build({ completion.choice, { "run " } }) )
-    end
-end
-local function completeAlias( shell, nIndex, sText, tPreviousText )
-    if nIndex == 2 then
-        return shell.completeProgram( sText )
-    end
-end
-local function completePeripheral( shell, nIndex, sText, tPreviousText )
-    if nIndex == 1 then
-        return completePeripheralName( sText )
-    end
-end
-local tGPSOptions = { "host", "host ", "locate" }
-local function completeGPS( shell, nIndex, sText, tPreviousText )
-    if nIndex == 1 then
-        return completeMultipleChoice( sText, tGPSOptions )
-    end
-end
-local tLabelOptions = { "get", "get ", "set ", "clear", "clear " }
-local function completeLabel( shell, nIndex, sText, tPreviousText )
-    if nIndex == 1 then
-        return completeMultipleChoice( sText, tLabelOptions )
-    elseif nIndex == 2 then
-        return completePeripheralName( sText )
-    end
-end
-local function completeMonitor( shell, nIndex, sText, tPreviousText )
-    if nIndex == 1 then
-        return completePeripheralName( sText, true )
-    elseif nIndex == 2 then
-        return shell.completeProgram( sText )
-    end
-end
-local tRedstoneOptions = { "probe", "set ", "pulse " }
-local function completeRedstone( shell, nIndex, sText, tPreviousText )
-    if nIndex == 1 then
-        return completeMultipleChoice( sText, tRedstoneOptions )
-    elseif nIndex == 2 then
-        return completeSide( sText )
-    end
-end
-local tDJOptions = { "play", "play ", "stop " }
-local function completeDJ( shell, nIndex, sText, tPreviousText )
-    if nIndex == 1 then
-        return completeMultipleChoice( sText, tDJOptions )
-    elseif nIndex == 2 then
-        return completePeripheralName( sText )
-    end
-end
-local tPastebinOptions = { "put ", "get ", "run " }
-local function completePastebin( shell, nIndex, sText, tPreviousText )
-    if nIndex == 1 then
-        return completeMultipleChoice( sText, tPastebinOptions )
-    elseif nIndex == 2 then
-        if tPreviousText[2] == "put" then
-            return fs.complete( sText, shell.dir(), true, false )
-        end
-    end
-end
-local tChatOptions = { "host ", "join " }
-local function completeChat( shell, nIndex, sText, tPreviousText )
-    if nIndex == 1 then
-        return completeMultipleChoice( sText, tChatOptions )
-    end
-end
-local function completeSet( shell, nIndex, sText, tPreviousText )
-    if nIndex == 1 then
-        return completeMultipleChoice( sText, settings.getNames(), true )
-    end
-end
-local tCommands
-if commands then
-    tCommands = commands.list()
-end
-local function completeExec( shell, nIndex, sText, tPreviousText )
-    if nIndex == 1 and commands then
-        return completeMultipleChoice( sText, tCommands, true )
-    end
-end
-local tWgetOptions = { "run" }
-local function completeWget( shell, nIndex, sText, tPreviousText )
-    if nIndex == 1 then
-        return completeMultipleChoice( sText, tWgetOptions, true )
-    end
-end
-shell.setCompletionFunction( "rom/programs/alias.lua", completeAlias )
-shell.setCompletionFunction( "rom/programs/cd.lua", completeDir )
-shell.setCompletionFunction( "rom/programs/copy.lua", completeEitherEither )
-shell.setCompletionFunction( "rom/programs/delete.lua", completeEitherMany )
-shell.setCompletionFunction( "rom/programs/drive.lua", completeDir )
-shell.setCompletionFunction( "rom/programs/edit.lua", completeFile )
-shell.setCompletionFunction( "rom/programs/eject.lua", completePeripheral )
-shell.setCompletionFunction( "rom/programs/gps.lua", completeGPS )
-shell.setCompletionFunction( "rom/programs/help.lua", completeHelp )
-shell.setCompletionFunction( "rom/programs/id.lua", completePeripheral )
-shell.setCompletionFunction( "rom/programs/label.lua", completeLabel )
-shell.setCompletionFunction( "rom/programs/list.lua", completeDir )
-shell.setCompletionFunction( "rom/programs/mkdir.lua", completeFileMany )
-shell.setCompletionFunction( "rom/programs/monitor.lua", completeMonitor )
-shell.setCompletionFunction( "rom/programs/move.lua", completeEitherEither )
-shell.setCompletionFunction( "rom/programs/redstone.lua", completeRedstone )
-shell.setCompletionFunction( "rom/programs/rename.lua", completeEitherEither )
-shell.setCompletionFunction( "rom/programs/shell.lua", completeProgram )
-shell.setCompletionFunction( "rom/programs/type.lua", completeEither )
-shell.setCompletionFunction( "rom/programs/set.lua", completeSet )
-shell.setCompletionFunction( "rom/programs/advanced/bg.lua", completeProgram )
-shell.setCompletionFunction( "rom/programs/advanced/fg.lua", completeProgram )
-shell.setCompletionFunction( "rom/programs/fun/dj.lua", completeDJ )
-shell.setCompletionFunction( "rom/programs/fun/advanced/paint.lua", completeFile )
-shell.setCompletionFunction( "rom/programs/http/pastebin.lua", completePastebin )
-shell.setCompletionFunction( "rom/programs/rednet/chat.lua", completeChat )
-shell.setCompletionFunction( "rom/programs/command/exec.lua", completeExec )
-shell.setCompletionFunction( "rom/programs/http/wget.lua", completeWget )
 
 if turtle then
-    local tGoOptions = { "left", "right", "forward", "back", "down", "up" }
+    shell.setCompletionFunction( "rom/programs/turtle/go.lua", completion.build(
-    local function completeGo( shell, nIndex, sText )
+        { completion.choice, { "left", "right", "forward", "back", "down", "up" }, true, many = true }
-        return completeMultipleChoice( sText, tGoOptions, true)
+    ) )
+    shell.setCompletionFunction( "rom/programs/turtle/turn.lua", completion.build(
+        { completion.choice, { "left", "right" }, true, many = true }
+    ))
+    shell.setCompletionFunction( "rom/programs/turtle/equip.lua", completion.build(
+        nil,
+        { completion.choice, { "left", "right" } }
+    ) )
+    shell.setCompletionFunction( "rom/programs/turtle/unequip.lua", completion.build(
+        { completion.choice, { "left", "right" } }
+    ) )
 end
-    local tTurnOptions = { "left", "right" }
-    local function completeTurn( shell, nIndex, sText )
-            return completeMultipleChoice( sText, tTurnOptions, true )
-    end
-    local tEquipOptions = { "left", "right" }
-    local function completeEquip( shell, nIndex, sText )
-        if nIndex == 2 then
-            return completeMultipleChoice( sText, tEquipOptions )
-        end
-    end
-    local function completeUnequip( shell, nIndex, sText )
-        if nIndex == 1 then
-            return completeMultipleChoice( sText, tEquipOptions )
-        end
-    end
-    shell.setCompletionFunction( "rom/programs/turtle/go.lua", completeGo )
-    shell.setCompletionFunction( "rom/programs/turtle/turn.lua", completeTurn )
-    shell.setCompletionFunction( "rom/programs/turtle/equip.lua", completeEquip )
-    shell.setCompletionFunction( "rom/programs/turtle/unequip.lua", completeUnequip )
-end
-
 
 -- Run autorun files
 if fs.exists( "/rom/autorun" ) and fs.isDir( "/rom/autorun" ) then
     local tFiles = fs.list( "/rom/autorun" )
-    table.sort( tFiles )
+    for _, sFile in ipairs( tFiles ) do
-    for n, sFile in ipairs( tFiles ) do
         if string.sub( sFile, 1, 1 ) ~= "." then
             local sPath = "/rom/autorun/"..sFile
             if not fs.isDir( sPath ) then

src/test/resources/test-rom/spec/modules/cc/completion_spec.lua

@@ -0,0 +1,57 @@
+describe("cc.completion", function()
+    local c = require("cc.completion")
+
+    describe("choice", function()
+        it("provides all choices", function()
+            expect(c.choice("", { "some text", "some other", "other" }))
+                :same { "some text", "some other", "other" }
+        end)
+
+        it("provides a filtered list of choices", function()
+            expect(c.choice("som", { "some text", "some other", "other" }))
+                :same { "e text", "e other" }
+
+            expect(c.choice("none", { "some text", "some other", "other" }))
+                :same { }
+        end)
+
+        it("adds text if needed", function()
+            expect(c.choice("som", { "some text", "some other", "other" }, true))
+                :same { "e text ", "e other " }
+        end)
+    end)
+
+    describe("peripheral", function()
+        it("provides a choice of peripherals", function()
+            stub(peripheral, "getNames", function() return { "drive_0", "left" } end)
+
+            expect(c.peripheral("dri")):same { "ve_0" }
+            expect(c.peripheral("dri", true)):same { "ve_0 " }
+        end)
+    end)
+
+    describe("side", function()
+        it("provides a choice of sides", function()
+            expect(c.side("le")):same { "ft" }
+            expect(c.side("le", true)):same { "ft " }
+        end)
+    end)
+
+    describe("setting", function()
+        it("provides a choice of setting names", function()
+            stub(settings, "getNames", function() return { "shell.allow_startup", "list.show_hidden" } end)
+
+            expect(c.setting("li")):same { "st.show_hidden" }
+            expect(c.setting("li", true)):same { "st.show_hidden " }
+        end)
+    end)
+
+    describe("command", function()
+        it("provides a choice of command names", function()
+            stub(_G, "commands", { list = function() return { "list", "say" } end })
+
+            expect(c.command("li")):same { "st" }
+            expect(c.command("li", true)):same { "st " }
+        end)
+    end)
+end)

src/test/resources/test-rom/spec/modules/cc/shell/completion_spec.lua

@@ -0,0 +1,41 @@
+describe("cc.shell.completion", function()
+    local c = require "cc.shell.completion"
+
+    describe("dirOrFile", function()
+        it("completes both", function()
+            expect(c.dirOrFile(shell, "rom/")):same {
+                "apis/", "apis", "autorun/", "autorun", "help/", "help",
+                "modules/", "modules", "motd.txt", "programs/", "programs", "startup.lua"
+            }
+        end)
+
+        it("adds a space", function()
+            expect(c.dirOrFile(shell, "rom/", nil, true)):same {
+                "apis/", "apis ", "autorun/", "autorun ", "help/", "help ",
+                "modules/", "modules ", "motd.txt ", "programs/", "programs ", "startup.lua ",
+            }
+        end)
+    end)
+
+    describe("build", function()
+        it("completes multiple arguments", function()
+            local spec = c.build(
+                function() return { "a", "b", "c" } end,
+                nil,
+                { c.choice, { "d", "e", "f"} }
+            )
+
+            expect(spec(shell, 1, "")):same { "a", "b", "c" }
+            expect(spec(shell, 2, "")):same(nil)
+            expect(spec(shell, 3, "")):same { "d", "e", "f" }
+            expect(spec(shell, 4, "")):same(nil)
+        end)
+
+        it("supports variadic completions", function()
+            local spec = c.build({ function() return { "a", "b", "c" } end, many = true })
+
+            expect(spec(shell, 1, "")):same({ "a", "b", "c" })
+            expect(spec(shell, 2, "")):same({ "a", "b", "c" })
+        end)
+    end)
+end)

src/test/resources/test-rom/spec/programs/mkdir_spec.lua

@@ -23,7 +23,7 @@ describe("The mkdir program", function()
         io.open("/test-files.a.txt", "w"):close()
 
         local complete = shell.getCompletionInfo()["rom/programs/mkdir.lua"].fnComplete
-        expect(complete(shell, 1, "/test-files/", {})):same { "a/", "b/" }
+        expect(complete(shell, 1, "/test-files/", {})):same { "a/", "a", "b/", "b" }
-        expect(complete(shell, 2, "/test-files/", { "/" })):same { "a/", "b/" }
+        expect(complete(shell, 2, "/test-files/", { "/" })):same { "a/", "a", "b/", "b" }
     end)
 end)