sharness: expanded on readme

test/README.md

@@ -24,3 +24,66 @@ Please do not change anything in the "lib/sharness" directory.
 If you really need some changes in sharness, please fork it from
 [its cannonical repo](https://github.com/mlafeldt/sharness/) and
 send pull requests there.
+
+## Writing Tests
+
+
+### Diagnostics
+
+Make your test case output helpful for when running sharness verbosely.
+This means cating certain files, or running diagnostic commands.
+For example:
+
+```
+test_expect_success ".go-ipfs/ has been created" '
+  test -d ".go-ipfs" &&
+  test -f ".go-ipfs/config" &&
+  test -d ".go-ipfs/datastore" ||
+  fsh ls -al .go-ipfs
+'
+```
+
+The `|| ...` is a diagnostic run when the preceding command fails.
+`bin/fsh` is a trivial script that echoes the args, runs the cmd,
+and then also fails, making sure the test case fails. (wouldnt want
+the diagnostic accidentally returning true and making it _seem_ like
+the test case succeeded!).
+
+
+### Testing commands on daemon or mounted
+
+Use the provided functions in `lib/test-lib.sh` to run the daemon or mount:
+
+To init, run daemon, and mount in one go:
+
+```sh
+test_launch_ipfs_daemon_and_mount
+
+test_expect_success "'ipfs add --help' succeeds" '
+  ipfs add --help >actual
+'
+
+# other tests here...
+
+# dont forget to kill the daemon!!
+test_kill_ipfs_daemon
+```
+
+To init, run daemon, and then mount separately:
+
+```sh
+test_init_ipfs
+
+# tests inited but not running here
+
+test_launch_ipfs_daemon
+
+# tests running but not mounted here
+
+test_mount_ipfs
+
+# tests mounted here
+
+# dont forget to kill the daemon!!
+test_kill_ipfs_daemon
+```