canonicalization is sometimes failing to return any results for links to extension methods

[natebosch]

I have an extension CoreChecks which is in scope, that extension defines a method equals. I hoped that a doc comment /// [CoreChecks.equals] would have a link to the docs for equals, but it renders as a code block instead of a link.

The analyzer jump to definition does work so this is a case where analyzer and dart doc disagree about comment references.

[jcollins-g]

dartdoc does not print an error message and so knows what this refers to but doesn't link it for some reason.

[jamesderlin]

Links to extension methods seem to work in some of the cases where I've tried it, so maybe there's something weird about this specific case? (The cases I tried were within the same .dart file where the extension was defined, however.)

[jcollins-g]

I spent a bit of time spelunking and this is a specific problem related to the example; most links work, however it seems that canonicalization is not returning correct results in this case. To explain briefly, first Dartdoc asks "where does this comment reference point to in the code". Here it gets the same result as the analyzer... all good. However, then Dartdoc tries to figure out "where is this code actually documented", so it can generate a link. This is complicated because the same bit of code can appear in the API surface of multiple libraries or classes depending on inheritance and the import/export graph. Dartdoc is not figuring this part out correctly, hence the missing link.