test: Uniformly canonicalize actual and expected JSON

Previously, we used a variety of ad-hoc canonicalizations for JSON
output in the test suite, but were ultimately very sensitive to JSON
irrelevancies such as whitespace.  This introduces a new test
comparison function, test_expect_equal_json, that first pretty-prints
*both* the actual and expected JSON and the compares the result.

The current implementation of this simply uses Python's json.tool to
perform pretty-printing (with a fallback to the identity function if
parsing fails).  However, since the interface it introduces is
semantically high-level, we could swap in other mechanisms in the
future, such as another pretty-printer or something that does not
re-order object keys (if we decide that we care about that).

In general, this patch does not remove the existing ad-hoc
canonicalization because it does no harm.  We do have to remove the
newline-after-comma rule from notmuch_json_show_sanitize and
filter_show_json because it results in invalid JSON that cannot be
pretty-printed.

Most of this patch simply replaces test_expect_equal and
test_expect_equal_file with test_expect_equal_json.  It changes the
expected JSON in a few places where sanitizers had placed newlines
after commas inside strings.

1 files changed, 4 insertions, 7 deletions

diff --git a/test/maildir-sync b/test/maildir-sync
index 01348d37..b748d040 100755
--- a/test/maildir-sync
+++ b/test/maildir-sync
@@ -4,11 +4,9 @@ test_description="maildir synchronization"
 
 . ./test-lib.sh
 
-# Much easier to examine differences if the "notmuch show
-# --format=json" output includes some newlines. Also, need to avoid
-# including the local value of MAIL_DIR in the result.
+# Avoid including the local value of MAIL_DIR in the result.
 filter_show_json() {
-    sed -e 's/, /,\n/g'  | sed -e "s|${MAIL_DIR}/|MAIL_DIR/|"
+    sed -e "s|${MAIL_DIR}/|MAIL_DIR/|"
     echo
 }
 
@@ -44,7 +42,7 @@ test_expect_equal "$output" "adding-replied-tag:2,RS"
 
 test_begin_subtest "notmuch show works with renamed file (without notmuch new)"
 output=$(notmuch show --format=json id:${gen_msg_id} | filter_show_json)
-test_expect_equal "$output" '[[[{"id": "adding-replied-tag@notmuch-test-suite",
+test_expect_equal_json "$output" '[[[{"id": "adding-replied-tag@notmuch-test-suite",
 "match": true,
 "excluded": false,
 "filename": "MAIL_DIR/cur/adding-replied-tag:2,RS",
@@ -54,8 +52,7 @@ test_expect_equal "$output" '[[[{"id": "adding-replied-tag@notmuch-test-suite",
 "headers": {"Subject": "Adding replied tag",
 "From": "Notmuch Test Suite <test_suite@notmuchmail.org>",
 "To": "Notmuch Test Suite <test_suite@notmuchmail.org>",
-"Date": "Fri,
-05 Jan 2001 15:43:57 +0000"},
+"Date": "Fri, 05 Jan 2001 15:43:57 +0000"},
 "body": [{"id": 1,
 "content-type": "text/plain",
 "content": "This is just a test message (#3)\n"}]},