run-tests: collect aggregate code coverage
Before this patch, every Python process during a code coverage run was
writing coverage data to the same file. I'm not sure if the coverage
package even tries to obtain a lock on the file. But what I do know is
there was some last write wins leading to loss of code coverage data, at
least with -j > 1.
This patch changes the code coverage mechanism to be multiple process
safe. The mechanism for initializing code coverage via sitecustomize.py
has been tweaked so each Python process will produce a separate coverage
data file on disk. Unless two processes generate the same random value,
there are no race conditions writing to the same file. At the end of the
test run, we combine all written files into an aggregate report.
On my machine, running the full test suite produces a little over
20,000 coverage files consuming ~350 MB. As you can imagine, it takes
several seconds to load and merge these coverage files. But when it is
done, you have an accurate picture of the aggregate code coverage for the
entire test suite, which is ~60% line coverage.
Set up a repo
$ cat <<EOF >> $HGRCPATH
> [ui]
> interactive = true
> [experimental]
> crecord = true
> crecordtest = testModeCommands
> EOF
$ hg init a
$ cd a
Committing some changes but stopping on the way
$ echo "a" > a
$ hg add a
$ cat <<EOF >testModeCommands
> TOGGLE
> X
> EOF
$ hg commit -i -m "a" -d "0 0"
no changes to record
$ hg tip
changeset: -1:000000000000
tag: tip
user:
date: Thu Jan 01 00:00:00 1970 +0000
Committing some changes
$ cat <<EOF >testModeCommands
> X
> EOF
$ hg commit -i -m "a" -d "0 0"
$ hg tip
changeset: 0:cb9a9f314b8b
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
Committing only one file
$ echo "a" >> a
>>> open('b', 'wb').write("1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n")
$ hg add b
$ cat <<EOF >testModeCommands
> TOGGLE
> KEY_DOWN
> X
> EOF
$ hg commit -i -m "one file" -d "0 0"
$ hg tip
changeset: 1:fb2705a663ea
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: one file
$ hg cat -r tip a
a
$ cat a
a
a
Committing only one hunk
- Untoggle all the hunks, go down to the second file
- unfold it
- go down to second hunk (1 for the first hunk, 1 for the first hunkline, 1 for the second hunk, 1 for the second hunklike)
- toggle the second hunk
- commit
$ echo "x" > c
$ cat b >> c
$ echo "y" >> c
$ mv c b
$ cat <<EOF >testModeCommands
> A
> KEY_DOWN
> f
> KEY_DOWN
> KEY_DOWN
> KEY_DOWN
> KEY_DOWN
> TOGGLE
> X
> EOF
$ hg commit -i -m "one hunk" -d "0 0"
$ hg tip
changeset: 2:7d10dfe755a8
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: one hunk
$ hg cat -r tip b
1
2
3
4
5
6
7
8
9
10
y
$ cat b
x
1
2
3
4
5
6
7
8
9
10
y
$ hg commit -m "other hunks"
$ hg tip
changeset: 3:a6735021574d
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: other hunks
$ hg cat -r tip b
x
1
2
3
4
5
6
7
8
9
10
y
Editing patch of newly added file
$ cat > editor.sh << '__EOF__'
> cat "$1" | sed "s/first/very/g" > tt
> mv tt "$1"
> __EOF__
$ cat > newfile << '__EOF__'
> This is the first line
> This is the second line
> This is the third line
> __EOF__
$ hg add newfile
$ cat <<EOF >testModeCommands
> f
> KEY_DOWN
> KEY_DOWN
> KEY_DOWN
> e
> X
> EOF
$ HGEDITOR="\"sh\" \"`pwd`/editor.sh\"" hg commit -i -d '23 0' -medit-patch-new
$ hg tip
changeset: 4:6a0a43e9eff5
tag: tip
user: test
date: Thu Jan 01 00:00:23 1970 +0000
summary: edit-patch-new
$ hg cat -r tip newfile
This is the very line
This is the second line
This is the third line
$ cat newfile
This is the first line
This is the second line
This is the third line
Newly added files can be selected with the curses interface
$ hg update -C .
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo "hello" > x
$ hg add x
$ cat <<EOF >testModeCommands
> TOGGLE
> TOGGLE
> X
> EOF
$ hg st
A x
? editor.sh
? testModeCommands
$ hg commit -i -m "newly added file" -d "0 0"
$ hg st
? editor.sh
? testModeCommands