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, 13 insertions, 4 deletions

diff --git a/test/test-lib.sh b/test/test-lib.sh
index 06aaea27..791d2dc6 100644
--- a/test/test-lib.sh
+++ b/test/test-lib.sh
@@ -512,6 +512,16 @@ test_expect_equal_file ()
     fi
 }
 
+# Like test_expect_equal, but arguments are JSON expressions to be
+# canonicalized before diff'ing.  If an argument cannot be parsed, it
+# is used unchanged so that there's something to diff against.
+test_expect_equal_json () {
+    output=$(echo "$1" | python -mjson.tool || echo "$1")
+    expected=$(echo "$2" | python -mjson.tool || echo "$2")
+    shift 2
+    test_expect_equal "$output" "$expected" "$@"
+}
+
 test_emacs_expect_t () {
 	test "$#" = 2 && { prereq=$1; shift; } || prereq=
 	test "$#" = 1 ||
@@ -565,10 +575,9 @@ notmuch_show_sanitize_all ()
 
 notmuch_json_show_sanitize ()
 {
-    sed -e 's|, |,\n |g' | \
-	sed \
-	-e 's|"id": "[^"]*",|"id": "XXXXX",|' \
-	-e 's|"filename": "[^"]*",|"filename": "YYYYY",|'
+    sed \
+	-e 's|"id": "[^"]*",|"id": "XXXXX",|g' \
+	-e 's|"filename": "[^"]*",|"filename": "YYYYY",|g'
 }
 
 # End of notmuch helper functions