tests/test-lrucachedict.py

color: turn 'ui.color' into a boolean (auto or off)

Previously, 'ui.color=yes' meant "always show color", While
"ui.color=auto" meant "use color automatically when it appears
sensible".

This feels problematic to some people because if an administrator has
disabled color with "ui.color=off", and a user turn it back  on using
"color=on", it will get surprised (because it breaks their output when
redirected to a file.) This patch changes ui.color=true to only move the
default value of --color from "never" to "auto".

I'm not really in favor of this changes as I suspect the above case will
be pretty rare and I would rather keep the logic simpler. However, I'm
providing this patch to help the 4.2 release in the case were others
decide to make this changes.

Users that want to force colors without specifying --color on the
command line can use the 'ui.formatted' config knob, which had to be
enabled in a handful of tests for this patch.

Nice summary table (credit: Augie Fackler)

That is, before this patch:

+--------------------+--------------------+--------------------+
|                    | not a tty          | a tty              |
|                    | --color not set    | --color not set    |
|                    |                    |                    |
+--------------------+--------------------+--------------------+
| [ui]               |                    |                    |
| color (not set)    | no color           | no color           |
|                    |                    |                    |
+--------------------+--------------------+--------------------+
| [ui]               |                    |                    |
| color = auto       | no color           | color              |
|                    |                    |                    |
+--------------------+--------------------+--------------------+
| [ui]               |                    |                    |
| color = yes        | *color*            | color              |
|                    |                    |                    |
+--------------------+--------------------+--------------------+
| [ui]               |                    |                    |
| color = no         | no color           | no color           |
|                    |                    |                    |
+--------------------+--------------------+--------------------+
(if --color is specified, it always clobbers the setting in [ui])

and after this patch:

+--------------------+--------------------+--------------------+
|                    | not a tty          | a tty              |
|                    | --color not set    | --color not set    |
|                    |                    |                    |
+--------------------+--------------------+--------------------+
| [ui]               |                    |                    |
| color (not set)    | no color           | no color           |
|                    |                    |                    |
+--------------------+--------------------+--------------------+
| [ui]               |                    |                    |
| color = auto       | no color           | color              |
|                    |                    |                    |
+--------------------+--------------------+--------------------+
| [ui]               |                    |                    |
| color = yes        | *no color*         | color              |
|                    |                    |                    |
+--------------------+--------------------+--------------------+
| [ui]               |                    |                    |
| color = no         | no color           | no color           |
|                    |                    |                    |
+--------------------+--------------------+--------------------+
(if --color is specified, it always clobbers the setting in [ui])

from __future__ import absolute_import, print_function

from mercurial import (
    util,
)

def printifpresent(d, xs, name='d'):
    for x in xs:
        present = x in d
        print("'%s' in %s: %s" % (x, name, present))
        if present:
            print("%s['%s']: %s" % (name, x, d[x]))

def test_lrucachedict():
    d = util.lrucachedict(4)
    d['a'] = 'va'
    d['b'] = 'vb'
    d['c'] = 'vc'
    d['d'] = 'vd'

    # all of these should be present
    printifpresent(d, ['a', 'b', 'c', 'd'])

    # 'a' should be dropped because it was least recently used
    d['e'] = 've'
    printifpresent(d, ['a', 'b', 'c', 'd', 'e'])

    assert d.get('a') is None
    assert d.get('e') == 've'

    # touch entries in some order (get or set).
    d['e']
    d['c'] = 'vc2'
    d['d']
    d['b'] = 'vb2'

    # 'e' should be dropped now
    d['f'] = 'vf'
    printifpresent(d, ['b', 'c', 'd', 'e', 'f'])

    d.clear()
    printifpresent(d, ['b', 'c', 'd', 'e', 'f'])

    # Now test dicts that aren't full.
    d = util.lrucachedict(4)
    d['a'] = 1
    d['b'] = 2
    d['a']
    d['b']
    printifpresent(d, ['a', 'b'])

    # test copy method
    d = util.lrucachedict(4)
    d['a'] = 'va3'
    d['b'] = 'vb3'
    d['c'] = 'vc3'
    d['d'] = 'vd3'

    dc = d.copy()

    # all of these should be present
    print("\nAll of these should be present:")
    printifpresent(dc, ['a', 'b', 'c', 'd'], 'dc')

    # 'a' should be dropped because it was least recently used
    print("\nAll of these except 'a' should be present:")
    dc['e'] = 've3'
    printifpresent(dc, ['a', 'b', 'c', 'd', 'e'], 'dc')

    # contents and order of original dict should remain unchanged
    print("\nThese should be in reverse alphabetical order and read 'v?3':")
    dc['b'] = 'vb3_new'
    for k in list(iter(d)):
        print("d['%s']: %s" % (k, d[k]))

if __name__ == '__main__':
    test_lrucachedict()