extra_template_vars() sending wrong view_name for index

See https://github.com/simonw/museums/issues/20#issuecomment-609103663 - at some point between 286ed286b68793532c2a38436a08343b45cfbc91 and current master (e0e7a0facfc935a835cd73c720bc46661462f0b1 today) a bug was introduced where the extra_template_vars(request, view_name) plugin hook started being passed None instead of index for the view_name parameter on the site index page.

[simonw]

You start git bisect by giving it a known bad commit and a known good one:

git bisect start master 286ed28 

Then you tell it to start running your script:

git bisect run python ../datasette-issue-716/check_view_name.py

Here’s what I got:

(datasette) ~/Dropbox/Development/datasette $ git bisect start master 286ed28
Bisecting: 30 revisions left to test after this (roughly 5 steps)
[dc80e779a2e708b2685fc641df99e6aae9ad6f97] Handle scope path if it is a string
(datasette) ~/Dropbox/Development/datasette $ git bisect run python ../datasette-issue-716/check_view_name.py
running python ../datasette-issue-716/check_view_name.py
Traceback (most recent call last):
...
Bisecting: 15 revisions left to test after this (roughly 4 steps)
[7c6a9c35299f251f9abfb03fd8e85143e4361709] Better tests for prepare_connection() plugin hook, refs #678
running python ../datasette-issue-716/check_view_name.py
Traceback (most recent call last):
...
Bisecting: 7 revisions left to test after this (roughly 3 steps)
[0091dfe3e5a3db94af8881038d3f1b8312bb857d] More reliable tie-break ordering for facet results
running python ../datasette-issue-716/check_view_name.py
Traceback (most recent call last):
...
Bisecting: 3 revisions left to test after this (roughly 2 steps)
[ce12244037b60ba0202c814871218c1dab38d729] Release notes for 0.35
running python ../datasette-issue-716/check_view_name.py
Traceback (most recent call last):
...
Bisecting: 0 revisions left to test after this (roughly 1 step)
[4d7dae9eb75e5430c3ee3c369bb5cd9ba0a148bc] Added a bunch more plugins to the Ecosystem page
running python ../datasette-issue-716/check_view_name.py
Traceback (most recent call last):
...
70b915fb4bc214f9d064179f87671f8a378aa127 is the first bad commit
commit 70b915fb4bc214f9d064179f87671f8a378aa127
Author: Simon Willison <[e-mail]>
Date:   Tue Feb 4 12:26:17 2020 -0800

    Datasette.render_template() method, closes #577
    
    Pull request #664.

:040000 040000 def9e31252e056845609de36c66d4320dd0c47f8 da19b7f8c26d50a4c05e5a7f05220b968429725c M	datasette
bisect run success

So 70b915fb4bc214f9d064179f87671f8a378aa127 introduced the bug!

[simonw]

The test ended up being a bit fiddly - here it is:

https://github.com/simonw/datasette/blob/09253817dea3c131553494f9b2eb9c03f94ae761/tests/test_plugins.py#L266-L317

I used tmp_path_factory here because the tmpdir fixture I usually use isn’t compatible with scope="session", and I wanted to only create those temporary plugins and templates directories once rather than create them for each run of the parametrized test function.

In writing this I realized that the name on the QueryView class wasn’t being used, because that class is currently just used for its .data() method:

https://github.com/simonw/datasette/blob/09253817dea3c131553494f9b2eb9c03f94ae761/datasette/views/database.py#L27-L31

https://github.com/simonw/datasette/blob/07e208cc6d9e901b87552c1be2854c220b3f9b6d/datasette/views/table.py#L224-L227

So I removed the name = "query" line since it was misleading.