From 83efa26e56e108f32da37c79bdeeb809e1dcae12 Mon Sep 17 00:00:00 2001
From: Daniel Silverstone <dsilvers@digital-scurf.org>
Date: Sun, 13 May 2012 20:36:18 +0100
Subject: Behaviour for 'default' in lace.builtin

---
 lib/lace/builtin.lua       | 31 ++++++++++++++++++++++
 test/test-lace.builtin.lua | 65 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+)

diff --git a/lib/lace/builtin.lua b/lib/lace/builtin.lua
index 209916d..a45051f 100644
--- a/lib/lace/builtin.lua
+++ b/lib/lace/builtin.lua
@@ -13,6 +13,8 @@ local function compiler()
    return require "lace.compiler"
 end
 
+--[ Allow and Deny ]------------------------------------------------
+
 local function _do_return(exec_context, result, reason, cond)
    if #cond > 0 then
       -- Run the conditions
@@ -40,6 +42,35 @@ end
 builtin.allow = _return
 builtin.deny = _return
 
+--[ Default for Allow and Deny ]------------------------------------
+
+function builtin.default(compcontext, def, result, reason, unwanted)
+   assert(def == "default", "Somehow, builtin.default got something odd")
+   if type(result) ~= "string" then
+      return compiler().error("Expected result, got nothing")
+   end
+   if result ~= "allow" and result ~= "deny" then
+      return compiler().error("Result wasn't allow or deny", {2})
+   end
+   if type(reason) ~= "string" then
+      reason = "Default behaviour"
+   end
+   if unwanted ~= nil then
+      return compiler().error("Unexpected additional content", {4})
+   end
+
+   if compcontext[".lace"].default then
+      return compiler().error("Cannot change the default")
+   end
+
+   compcontext[".lace"].default = { result, reason }
+
+   return {
+      fn = function() return true end,
+      args = {}
+   }
+end
+
 return {
    commands = builtin,
 }
diff --git a/test/test-lace.builtin.lua b/test/test-lace.builtin.lua
index 67f0166..10c5c8f 100644
--- a/test/test-lace.builtin.lua
+++ b/test/test-lace.builtin.lua
@@ -61,6 +61,71 @@ function suite.run_builtin_allow_deny_novariables()
    assert(msg == "because", "Expected reason should be 'because'")
 end
 
+function suite.compile_builtin_default_noresult()
+   local compctx = {[".lace"] = {}}
+   local cmdtab, msg = builtin.commands.default(compctx, "default")
+   assert(cmdtab == false, "Internal errors should return false")
+   assert(type(msg) == "table", "Internal errors should return tables")
+   assert(type(msg.msg) == "string", "Internal errors should have string messages")
+   assert(msg.msg:match("Expected result"), "Expected error should mention a lack of result")
+end
+
+function suite.compile_builtin_default_resultbad()
+   local compctx = {[".lace"] = {}}
+   local cmdtab, msg = builtin.commands.default(compctx, "default", "FISH")
+   assert(cmdtab == false, "Internal errors should return false")
+   assert(type(msg) == "table", "Internal errors should return tables")
+   assert(type(msg.msg) == "string", "Internal errors should have string messages")
+   assert(msg.msg:match("allow or deny"), "Expected error should mention a bad of result")
+end
+
+function suite.compile_builtin_default_extra_fluff()
+   local compctx = {[".lace"] = {}}
+   local cmdtab, msg = builtin.commands.default(compctx, "default", "allow", "", "unwanted")
+   assert(cmdtab == false, "Internal errors should return false")
+   assert(type(msg) == "table", "Internal errors should return tables")
+   assert(type(msg.msg) == "string", "Internal errors should have string messages")
+   assert(msg.msg:match("additional"), "Expected error should mention additional content")
+end
+
+function suite.compile_builtin_default_ok()
+   local compctx = {[".lace"] = {}}
+   local cmdtab, msg = builtin.commands.default(compctx, "default", "allow", "because")
+   assert(type(cmdtab) == "table", "Successful compilation should return a table")
+   assert(type(cmdtab.fn) == "function", "With a function")
+   assert(type(cmdtab.args) == "table", "And an arg table")
+   assert(cmdtab.fn() == true, "Default command should always return true")
+   assert(type(compctx[".lace"].default) == "table", "Default should always set up the context")
+   assert(#compctx[".lace"].default == 2, "Default table should consist of two entries")
+   assert(compctx[".lace"].default[1] == "allow", "First entry should be the result")
+   assert(compctx[".lace"].default[2] == "because", "Second entry should be the reason")
+end
+
+function suite.compile_builtin_default_twice()
+   local compctx = {[".lace"] = {}}
+   local cmdtab, msg = builtin.commands.default(compctx, "default", "allow", "")
+   assert(type(cmdtab) == "table", "Successful compilation should return a table")
+   local cmdtab, msg = builtin.commands.default(compctx, "default", "allow", "")
+   assert(cmdtab == false, "Internal errors should return false")
+   assert(type(msg) == "table", "Internal errors should return tables")
+   assert(type(msg.msg) == "string", "Internal errors should have string messages")
+   assert(msg.msg:match("change the"), "Expected error should mention changing the default")
+end
+
+function suite.compile_builtin_default_noreason()
+   local compctx = {[".lace"] = {}}
+   local cmdtab, msg = builtin.commands.default(compctx, "default", "allow")
+   assert(type(cmdtab) == "table", "Successful compilation should return a table")
+   assert(type(cmdtab.fn) == "function", "With a function")
+   assert(type(cmdtab.args) == "table", "And an arg table")
+   assert(cmdtab.fn() == true, "Default command should always return true")
+   assert(type(compctx[".lace"].default) == "table", "Default should always set up the context")
+   assert(#compctx[".lace"].default == 2, "Default table should consist of two entries")
+   assert(compctx[".lace"].default[1] == "allow", "First entry should be the result")
+   assert(compctx[".lace"].default[2] == "Default behaviour", "Second entry should be the reason")
+end
+
+
 local count_ok = 0
 for _, testname in ipairs(testnames) do
    print("Run: " .. testname)
-- 
cgit v1.2.1