make sure shebang is always emitted first

Author: CapsAdmin

nattlua/emitter/base.lua

@@ -508,6 +508,18 @@ return function()
 	end
 
 	function META:BuildCode(block)
+		local statements = block.statements
+		local first_statement = statements and statements[1]
+		local has_leading_shebang = first_statement and first_statement.Type == "statement_shebang"
+
+		if has_leading_shebang then
+			self:EmitStatement(first_statement)
+
+			if statements[2] or (block.imports and not self.config.skip_import) then
+				self:Whitespace("\n")
+			end
+		end
+
 		if block.imports and not self.config.skip_import then
 			self.done = {}
 			self:EmitNonSpace("_G.IMPORTS = _G.IMPORTS or {}\n")
@@ -564,7 +576,18 @@ return function()
 			end
 		end
 
-		self:EmitStatements(block.statements)
+		if has_leading_shebang then
+			local remaining = {}
+
+			for i = 2, #statements do
+				remaining[#remaining + 1] = statements[i]
+			end
+
+			self:EmitStatements(remaining)
+		else
+			self:EmitStatements(statements)
+		end
+
 		local str = self:Concat()
 
 		if self.config.trailing_newline and str:find("\n", nil, true) then

test/tests/nattlua/emitter.lua

@@ -21,6 +21,30 @@ local function identical(str)
 	check({pretty_print = true}, str)
 end
 
+do
+	local output = assert(
+		nl.Compiler(
+			[[#!/usr/bin/env lua
+local dep = import("./shebang_import_dep.nlua")]],
+			nil,
+			{
+				parser = {
+					working_directory = "test/tests/nattlua/",
+					emit_environment = false,
+				},
+				emitter = {
+					pretty_print = true,
+					force_parenthesis = true,
+					string_quote = "\"",
+				},
+			}
+		):Emit()
+	)
+
+	assert(output:find("^#!/usr/bin/env lua\n_G%.IMPORTS = _G%.IMPORTS or %{%}\n") ~= nil)
+	assert(select(2, output:gsub("#!", "")) == 1)
+end
+
 check(
 	{pretty_print = true, force_parenthesis = true, string_quote = "\""},
 	[[local foo = aaa 'aaa'-- dawdwa

test/tests/nattlua/shebang_import_dep.nlua

@@ -0,0 +1,3 @@
+return {
+	ok = true,
+}