Use exception to handle exit instead of exiting the process directly

Author: MatheusRich

spec/spec_helper.cr

@@ -24,12 +24,16 @@ def run_lit_in_process(*args)
 end
 
 def run_lit(file)
-  result = nil
+  status = Process::Status.new(0)
   full_output = output_of {
-    result, _ = Lit::Lit.run(File.read(file))
+    begin
+      result = Lit::Lit.run_file(file)
+      status = Process::Status.new(result.ok? ? 0 : 1)
+    rescue e : Lit::Interpreter::Exit
+      status = Process::Status.new(e.status.to_i)
+    end
   }
 
-  status = Process::Status.new(result ? 0 : 1)
   {status, full_output}
 end
 

src/lit.cr

@@ -26,10 +26,14 @@ module Lit
       end
     end
 
-    if opts.first?
-      exit(Lit.run_file(opts.first).to_i)
-    else
-      Lit.run_repl
+    begin
+      if opts.first?
+        exit(Lit.run_file(opts.first).to_i)
+      else
+        Lit.run_repl
+      end
+    rescue e : ::Lit::Interpreter::Exit
+      exit(e.status.to_i)
     end
   end
 end

src/lit/interpreter.cr

@@ -32,6 +32,12 @@ module Lit
       def initialize(@value); end
     end
 
+    class Exit < Exception
+      getter status : Int64
+
+      def initialize(@status); end
+    end
+
     class Next < Exception; end
 
     getter environment # current environment

src/lit/stdlib/native.cr

@@ -70,9 +70,9 @@ module Lit
           }),
           ::Lit::Native::Fn.new("exit", 0..1, ->(interpreter : Interpreter, arguments : ::Array(Value), token : Token) : Value {
             if arguments.empty?
-              exit
+              raise Interpreter::Exit.new(0)
             elsif arguments[0].is_a?(Int64)
-              exit(arguments[0].as(Int64).to_i32)
+              raise Interpreter::Exit.new(arguments[0].as(Int64).to_i32)
             else
               raise RuntimeError.new(token, "Expected number as the first argument, got #{interpreter.type_of(arguments[0])}.")
             end