Give extended info about parse/compile errors

elia · elia · commit d2e435b4c8f1 · 2015-01-16T00:53:40.000+01:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,7 @@
 ## edge (upcoming 0.7)
 
+*   Show extended info and context upon parsing, compiling and building errors
+
 *   Support keyword arguments in method calls and definitions.
 
 *   Fix `begin`/`rescue` blocks to evaluate to last expression.
diff --git a/lib/opal/builder.rb b/lib/opal/builder.rb
@@ -38,9 +38,9 @@ def build_str source, filename, options = {}
       requires.map { |r| process_require(r, options) }
       processed << asset
       self
-    rescue MissingRequire
-      $stdout.puts "A file required by #{filename.inspect} wasn't found."
-      raise
+    rescue MissingRequire => error
+      error.message = "A file required by #{filename.inspect} wasn't found.\n#{error.message}"
+      raise error
     end
 
     def build_require(path, options = {})
@@ -124,9 +124,9 @@ def process_require(filename, options)
 
     def process_requires(source_filename, requires, options)
       requires.map { |r| process_require(r, options) }
-    rescue MissingRequire
-      $stdout.puts "A file required by #{source_filename.inspect} wasn't found."
-      raise
+    rescue MissingRequire => error
+      error.message = "A file required by #{filename.inspect} wasn't found.\n#{error.message}"
+      raise error
     end
 
     def already_processed
diff --git a/lib/opal/compiler.rb b/lib/opal/compiler.rb
@@ -135,6 +135,9 @@ def compile
       @fragments = process(@sexp).flatten
 
       @result = @fragments.map(&:code).join('')
+    rescue => error
+      message = "An error occurred while compiling: #{self.file}\n#{error.message}"
+      raise error.class, message
     end
 
     # Returns a source map that can be used in the browser to map back to
diff --git a/lib/opal/parser.rb b/lib/opal/parser.rb
@@ -36,15 +36,16 @@ def parse(source, file = '(string)')
       @lexer.parser = self
 
       self.parse_to_sexp
-    rescue => e
-      if $DEBUG || $VERBOSE
-        $stderr.puts
-        $stderr.puts e
-        $stderr.puts "Source: #{@file}:#{lexer.line}:#{lexer.column}"
-        $stderr.puts source.split("\n")[lexer.line-1]
-        $stderr.puts '~'*lexer.column + '^'
-      end
-      raise e
+    rescue => error
+      message = [
+        nil,
+        error.message,
+        "Source: #{@file}:#{lexer.line}:#{lexer.column}",
+        source.split("\n")[lexer.line-1],
+        '~'*(lexer.column-1) + '^',
+      ].join("\n")
+
+      raise error.class, message
     end
 
     def parse_to_sexp
