add last-modified/if-modified-since cache header processing

README.md

@@ -93,7 +93,7 @@ Deprecate a version of a package in the registry.
 * `cb` {Function}
 
 Fetches data from the registry via a GET request, saving it in the cache folder
-with the ETag.
+with the ETag or the "Last Modified" timestamp.
 
 ### client.publish(uri, params, cb)
 
@@ -182,6 +182,7 @@ caching logic directly.
     that are not Buffers or Streams are encoded as JSON. Optional – body
     only used for write operations.
   * `etag` {String} The cached ETag. Optional.
+  * `lastModified` {String} The cached Last-Modified timestamp. Optional.
   * `follow` {Boolean} Follow 302/301 responses. Optional (default: true).
   * `auth` {Credentials} Optional.
 * `cb` {Function}

lib/request.js

@@ -121,6 +121,11 @@ function makeRequest (uri, params, cb_) {
     headers[params.method === "GET" ? "if-none-match" : "if-match"] = params.etag
   }
 
+  if (params.lastModified && params.method === "GET") {
+    this.log.verbose("lastModified", params.lastModified)
+    headers["if-modified-since"] = params.lastModified;
+  }
+
   // figure out wth body is
   if (params.body) {
     if (Buffer.isBuffer(params.body)) {
@@ -139,6 +144,7 @@ function makeRequest (uri, params, cb_) {
     }
     else {
       delete params.body._etag
+      delete params.body._lastModified
       opts.json = params.body
     }
   }
@@ -220,6 +226,10 @@ function requestDone (method, where, cb) {
       parsed._etag = response.headers.etag
     }
 
+    if (parsed && response.headers['last-modified']) {
+      parsed._lastModified = response.headers['last-modified']
+    }
+
     // for the search endpoint, the "error" property can be an object
     if (parsed && parsed.error && typeof parsed.error !== "object" ||
         response.statusCode >= 400) {

test/request.js

@@ -81,7 +81,7 @@ test("request call contract", function (t) {
 })
 
 test("run request through its paces", function (t) {
-  t.plan(24)
+  t.plan(27)
 
   server.expect("/request-defaults", function (req, res) {
     t.equal(req.method, "GET", "uses GET by default")
@@ -94,6 +94,14 @@ test("run request through its paces", function (t) {
     }))
   })
 
+  server.expect("/last-modified", function (req, res) {
+    t.equal(req.headers["if-modified-since"], "test-last-modified",
+      "got test if-modified-since")
+
+    res.statusCode = 200
+    res.json({ fetched : "last-modified" })
+  })
+
   server.expect("/etag", function (req, res) {
     t.equal(req.headers["if-none-match"], "test-etag", "got test etag")
 
@@ -169,6 +177,12 @@ test("run request through its paces", function (t) {
     }
   )
 
+  var lastModified = { lastModified : "test-last-modified" }
+  client.request(common.registry+"/last-modified", lastModified, function (er, data) {
+    t.ifError(er, "call worked")
+    t.deepEquals(data, { fetched : "last-modified" }, "last-modified request sent")
+  })
+
   var etagged = { etag : "test-etag" }
   client.request(common.registry+"/etag", etagged, function (er, data) {
     t.ifError(er, "call worked")