feat(rest): extend wrapped results

whenever a wrapped result is returned from a request
to eXist-db's REST-API (for both GET and POST) the
response will be extended with metadata derived
from the <exist:result> elements attributes.

- hits
- start
- count
- session
- compilationTime
- executionTime

If any of the above attributes is not set the property is set
to -1.

components/rest.js

@@ -73,6 +73,17 @@ const postAttributeNames = [
   'cache'
 ]
 
+const existResultRegex = /^<exist:result/
+/**
+ * Tests if body is a wrapped result from exist=db
+ *
+ * @param {String} body server response body
+ * @returns {Boolean}
+ */
+function isExistResult (body) {
+  return existResultRegex.test(body)
+}
+
 const sessionRegex = /exist:session="(\d+)"/
 const hitsRegex = /exist:hits="(\d+)"/
 const startRegex = /exist:start="(\d+)"/
@@ -91,6 +102,29 @@ function getAttributeValueByRegex (existResult, regex) {
   return regex.test(existResult) ? parseInt(regex.exec(existResult)[1], 10) : -1
 }
 
+function extendIfWrapped (response) {
+  const { body } = response
+  if (!isExistResult(body)) {
+    return response
+  }
+
+  const session = getAttributeValueByRegex(body, sessionRegex)
+  const hits = getAttributeValueByRegex(body, hitsRegex)
+  const start = getAttributeValueByRegex(body, startRegex)
+  const count = getAttributeValueByRegex(body, countRegex)
+  const compilationTime = getAttributeValueByRegex(body, compilationTimeRegex)
+  const executionTime = getAttributeValueByRegex(body, executionTimeRegex)
+
+  return Object.assign(response, {
+    session,
+    hits,
+    start,
+    count,
+    compilationTime,
+    executionTime
+  })
+}
+
 /**
  * create resource in DB
  * @param {Object} restClient Got-instance
@@ -136,25 +170,8 @@ async function post (restClient, query, path, options) {
     },
     body
   })
-  const existResult = response.body
-
-  const session = getAttributeValueByRegex(existResult, sessionRegex)
-  const hits = getAttributeValueByRegex(existResult, hitsRegex)
-  const start = getAttributeValueByRegex(existResult, startRegex)
-  const count = getAttributeValueByRegex(existResult, countRegex)
-  const compilationTime = getAttributeValueByRegex(existResult, compilationTimeRegex)
-  const executionTime = getAttributeValueByRegex(existResult, executionTimeRegex)
 
-  return {
-    session,
-    hits,
-    start,
-    count,
-    compilationTime,
-    executionTime,
-    body: existResult,
-    statusCode: response.statusCode
-  }
+  return extendIfWrapped(response)
 }
 
 /**
@@ -179,10 +196,11 @@ async function get (restClient, path, searchParams, writableStream) {
       readStream,
       writableStream
     )
-    return _response
+    return extendIfWrapped(_response)
   }
 
-  return restClient.get({ url, searchParams })
+  const response = await restClient.get({ url, searchParams })
+  return extendIfWrapped(response)
 }
 
 /**

spec/tests/rest.js

@@ -246,11 +246,11 @@ test('with rest client', async function (t) {
     try {
       const res = await rc.get('db/rest-test', { _wrap: 'yes', _indent: 'yes', _query })
       st.equal(res.statusCode, 200, 'server responded with status ' + res.statusCode)
-      const lines = res.body.split('\n')
       st.equal(res.hits, 1, 'result returned ' + res.hits + ' hit(s)')
       st.equal(res.start, 1, 'start is ' + res.start)
       st.equal(res.count, 1, 'count is ' + res.count)
 
+      const lines = res.body.split('\n')
       st.ok(lines[0].startsWith('<exist:result xmlns:exist="http://exist.sourceforge.net/NS/exist"'))
       st.equal(lines[1], '    <c name="/db/rest-test">')
       st.equal(lines[2], '        <r name="from-buffer.xml"/>')
@@ -292,7 +292,7 @@ test('with rest client', async function (t) {
       const lines = res.body.split('\n')
       st.equal(lines.length, 1, 'body consists of a single line')
       st.ok(lines[0].startsWith('<exist:result xmlns:exist="http://exist.sourceforge.net/NS/exist"'))
-      st.ok(lines[0].contains('<c name="/db/rest-test">'), 'contains result')
+      st.ok(lines[0].includes('<c name="/db/rest-test">'), 'contains result')
       st.end()
     } catch (e) {
       st.fail(e)
@@ -341,7 +341,7 @@ test('with rest client', async function (t) {
     try {
       const res = await rc.post('xmldb:get-child-resources("/db/rest-test")', 'db/rest-test', { cache: 'yes', start: 1, max: 1 })
       st.equal(res.statusCode, 200, 'server responded with status ' + res.statusCode)
-      st.ok(res.session, 'Got session ' + res.session)
+      st.isNot(res.session, -1, 'Got session ' + res.session)
       st.equal(res.hits, 7, 'result returned ' + res.hits + ' hit(s)')
       st.equal(res.start, 1, 'start is ' + res.start)
       st.equal(res.count, 1, 'count is ' + res.count)