The JavaScript warning "Using
//@
to indicate sourceURL pragmas is deprecated. Use
//#
instead" occurs when there is a deprecated source map syntax in a JavaScript source.
Warning: SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead Warning: SyntaxError: Using //@ to indicate sourceMappingURL pragmas is deprecated. Use //# instead
A warning that a
SyntaxError
occurred. JavaScript execution won't be halted.
There is a deprecated source map syntax in a JavaScript source.
JavaScript sources are often combined and minified to make delivering them from the server more efficient. With source maps , the debugger can map the code being executed to the original source files.
The source map specification changed the syntax due to a conflict with IE whenever it was found in the page after
//@cc_on
was interpreted to turn on conditional compilation in the IE JScript engine. The
conditional compilation comment
in IE is a little known feature, but it broke source maps with
jQuery
and other libraries.
Syntax with the "@" sign is deprecated.
//@ sourceMappingURL=http://example.com/path/to/your/sourcemap.map
Use the "#" sign instead.
//# sourceMappingURL=http://example.com/path/to/your/sourcemap.map
Or, alternatively, you can set a
SourceMap
header to your JavaScript file to avoid having a comment at all:
SourceMap: /path/to/file.js.map
SourceMap