added usage instructions and a new set of tests

Author: aekeus

README.md

@@ -2,10 +2,36 @@
 
 database version control (postgres for now)
 
+# purpose
+
+verdb manages the execution of postgres DDL scripts. It expects to be executed
+in a directory containing list of sub-directories, each of which corresponds
+to a set of changes. The sub-directories must contain an 'up.sql' and a 'down.sql'
+script. (although these filename may be changed)
+
+The list, and order of the changes, must be maintained in a control file. This file
+is simply an order list of sub-directories. The pointer will point to a single
+sub-directory name contained in this file.
+
+verdb maintains a pointer to the last batch (directory) of ddl scripts that
+executed correctly.
+
 # example
 
 ```
 verdb init database postgres batches
 verdb status
 verdb up all
 ```
+
+# install
+
+With [npm](https://npmjs.org) do:
+
+```
+sudo npm install verdb -g
+```
+
+# license
+
+MIT

test/set.coffee

@@ -0,0 +1,23 @@
+#!/usr/bin/env coffee
+test = require('tap').test
+set = require '../lib/set'
+
+test "set", (t) ->
+
+  consol =
+    log: (m) ->
+      t.equal m, "pointer set to v"
+
+  set.inject consol
+
+  nconf =
+    set: (k, v) ->
+      t.equal k, 'pointer', 'pointer set'
+      t.equal v, 'v', 'v set'
+
+  persist = (_nconf) ->
+    t.equal _nconf, nconf, "persist called with correct nconf"
+
+  set.run nconf, ['pointer', 'v'], persist
+
+  t.end()