docs(template): Fix newline option description (#467)

lua/pl/template.lua

@@ -115,7 +115,7 @@ function template.substitute(str,env)
         escape = rawget(env,"_escape"),
         inline_escape = rawget(env,"_inline_escape"),
         inline_brackets = rawget(env,"_brackets"),
-        newline = nil,
+        newline = false,
         debug = rawget(env,"_debug")
     })
     if not t then return t, err end
@@ -159,7 +159,7 @@ end
 --   * `escape`: character marking Lua lines, default is '#'
 --   * `inline_escape`: character marking inline Lua expression, default is '$'.
 --   * `inline_brackets`: bracket pair that wraps inline Lua expressions, default is '()'.
---   * `newline`: string to replace newline characters, default is `nil` (not replacing newlines).
+--   * `newline`: if truthy, newlines will be stripped from text in the template. Default is `false`.
 --   * `debug`: if truthy, the generated source code will be retained within the compiled template object, default is `nil`.
 --
 -- @string str the template string

tests/test-template.lua

@@ -184,7 +184,7 @@ local my_env = {
   ipairs = ipairs,
   T = {'one','two','three'}
 }
-local t, err = template.compile(tmpl, { debug = true, newline = "" })
+local t, err = template.compile(tmpl, { debug = true, newline = true })
 local res, err, code = t:render(my_env)
 --print(res, err, code)
 asserteq(res, [[some list: ONE,TWO,THREE]])
@@ -197,7 +197,7 @@ local tmpl = [[
 header: $("hello" * 10)
 ]]
 
-local t, err = template.compile(tmpl, { debug = true, newline = "" })
+local t, err = template.compile(tmpl, { debug = true, newline = true })
 local res, err, code = t:render()
 --print(res, err, code)
 assert(res == nil, "expected nil here because of the runtime error")
@@ -213,7 +213,7 @@ local tmpl = [[
 header: $(myParam)
 ]]
 
-local t, err = template.compile(tmpl, { debug = true, newline = "" })
+local t, err = template.compile(tmpl, { debug = true, newline = true })
 local myParam = {}
 local res, err, code = t:render( {myParam = myParam } ) -- insert a table
 --print(res, err, code)
@@ -232,7 +232,7 @@ local my_env = {
   ipairs = ipairs,
   T = {'one','two','three'}
 }
-local t, err, code = template.compile(tmpl, { debug = true, newline = "" })
+local t, err, code = template.compile(tmpl, { debug = true, newline = true })
 --print(t, err, code)
 assert(t==nil, "expected t to be nil here because of the syntax error")
 asserteq(type(err), "string")