Remove pathWithExtension

This doesn't actually do anything: paths will never have a trailing
slash, so it's just equivalent to `x..".lua"`.

projects/core/src/main/resources/data/computercraft/lua/rom/programs/shell.lua

@@ -350,16 +350,6 @@ function shell.resolve(path)
     end
 end
 
-local function pathWithExtension(_sPath, _sExt)
-    local nLen = #sPath
-    local sEndChar = string.sub(_sPath, nLen, nLen)
-    -- Remove any trailing slashes so we can add an extension to the path safely
-    if sEndChar == "/" or sEndChar == "\\" then
-        _sPath = string.sub(_sPath, 1, nLen - 1)
-    end
-    return _sPath .. "." .. _sExt
-end
-
 --- Resolve a program, using the [program path][`path`] and list of [aliases][`aliases`].
 --
 -- @tparam string command The name of the program
@@ -384,7 +374,7 @@ function shell.resolveProgram(command)
         if fs.exists(sPath) and not fs.isDir(sPath) then
             return sPath
         else
-            local sPathLua = pathWithExtension(sPath, "lua")
+            local sPathLua = sPath .. ".lua"
             if fs.exists(sPathLua) and not fs.isDir(sPathLua) then
                 return sPathLua
             end
@@ -398,7 +388,7 @@ function shell.resolveProgram(command)
         if fs.exists(sPath) and not fs.isDir(sPath) then
             return sPath
         else
-            local sPathLua = pathWithExtension(sPath, "lua")
+            local sPathLua = sPath .. ".lua"
             if fs.exists(sPathLua) and not fs.isDir(sPathLua) then
                 return sPathLua
             end

projects/core/src/test/resources/test-rom/spec/programs/shell_spec.lua

@@ -152,6 +152,18 @@ describe("The shell", function()
             shell.resolveProgram("ls")
             expect.error(shell.resolveProgram, nil):eq("bad argument #1 (string expected, got nil)")
         end)
+
+        it("finds files on the shell path", function()
+            expect(shell.resolveProgram("edit")):eq("rom/programs/edit.lua")
+            expect(shell.resolveProgram("edit.lua")):eq("rom/programs/edit.lua")
+        end)
+
+        it("finds programs even with a trailing slash", function()
+            -- This feels silly: "edit/" is a directory, not the name of a file. However,
+            -- fs.combine (and CC's other path normalisation code) strips trailing slashes,
+            -- so this should still resolve the program.
+            expect(shell.resolveProgram("/rom/programs/edit/")):eq("rom/programs/edit.lua")
+        end)
     end)
 
     describe("shell.complete", function()