Dump returns a Checker that always returns nil, and as a side-effect writes a human-readable description of n's subtree to standard output.

HasAttr returns a Checker that checks for an attribute with the given name whose value matches the given regular expression.

HasExactText returns a checker that checks whether the given string matches the node's text exactly.

HasExactTextCollapsed returns a checker that checks whether the given string matches the node's text with its leading, trailing, and redundant whitespace trimmed.

HasHref returns a Checker that checks whether the node has an "href" attribute with exactly val.

HasText returns a Checker that checks whether the given regexp matches the node's text.

In returns a Checker that applies the given checkers to the first node matching the CSS selector.

NotIn returns a checker that succeeds only if no nodes match selector.

Run is a convenience function to run the checker against HTML read from reader.

A Checker is a function from an HTML node to an error describing a failure.