Merge pull request #19 from dannyrb/fix/server-request-options-config…

…uration

Fix/server request options configuration

src/__mocks__/dicomweb-client.js

@@ -0,0 +1,15 @@
+// import { api } from 'dicomweb-client'
+
+const api = {
+  DICOMwebClient: jest.fn().mockImplementation(() => {
+    return {
+      retrieveStudyMetadata: jest.fn().mockResolvedValue([]),
+    }
+  }),
+}
+
+export default {
+  api,
+}
+
+export { api }

src/studies/retrieveStudyMetadata.js

@@ -1,66 +1,57 @@
-import log from '../log.js';
-import RetrieveMetadata from './services/wado/retrieveMetadata.js';
+import RetrieveMetadata from './services/wado/retrieveMetadata.js'
 
-// Define the StudyMetaDataPromises object. This is used as a cache to store study meta data
-// promises and prevent unnecessary subsequent calls to the server
-const StudyMetaDataPromises = new Map();
+const module = 'RetrieveStudyMetadata'
+// Cache for promises. Prevents unnecessary subsequent calls to the server
+const StudyMetaDataPromises = new Map()
 
 /**
- * Delete the cached study metadata retrieval promise to ensure that the browser will
- * re-retrieve the study metadata when it is next requested
- *
- * @param {String} studyInstanceUid The UID of the Study to be removed from cache
- *
- */
-export function deleteStudyMetadataPromise(studyInstanceUid) {
-  if (StudyMetaDataPromises.has(studyInstanceUid)) {
-    StudyMetaDataPromises.delete(studyInstanceUid);
-  }
-}
-
-/**
- * Retrieves study metadata using a server call
+ * Retrieves study metadata
  *
- * @param {String} studyInstanceUid The UID of the Study to be retrieved
+ * @param {Object} server
+ * @param {string} studyInstanceUid The UID of the Study to be retrieved
  * @returns {Promise} that will be resolved with the metadata or rejected with the error
  */
-export function retrieveStudyMetadata(
-  server,
-  studyInstanceUid,
-  seriesInstanceUids
-) {
+export function retrieveStudyMetadata(server, studyInstanceUid) {
   // @TODO: Whenever a study metadata request has failed, its related promise will be rejected once and for all
   // and further requests for that metadata will always fail. On failure, we probably need to remove the
   // corresponding promise from the "StudyMetaDataPromises" map...
 
-  // If the StudyMetaDataPromises cache already has a pending or resolved promise related to the
-  // given studyInstanceUid, then that promise is returned
-  if (StudyMetaDataPromises.has(studyInstanceUid)) {
-    return StudyMetaDataPromises.get(studyInstanceUid);
+  if (!server) {
+    throw new Error(`${module}: Required 'server' parameter not provided.`)
+  }
+  if (!studyInstanceUid) {
+    throw new Error(
+      `${module}: Required 'studyInstanceUid' parameter not provided.`
+    )
   }
 
-  const seriesKeys = Array.isArray(seriesInstanceUids)
-    ? '|' + seriesInstanceUids.join('|')
-    : '';
-  const timingKey = `retrieveStudyMetadata[${studyInstanceUid}${seriesKeys}]`;
-  log.time(timingKey);
+  // Already waiting on result? Return cached promise
+  if (StudyMetaDataPromises.has(studyInstanceUid)) {
+    return StudyMetaDataPromises.get(studyInstanceUid)
+  }
 
   // Create a promise to handle the data retrieval
   const promise = new Promise((resolve, reject) => {
-    // If no study metadata is in the cache variable, we need to retrieve it from
-    // the server with a call.
-    if (
-      server.type === 'dicomWeb' &&
-      server.requestOptions.requestFromBrowser === true
-    ) {
-      RetrieveMetadata(server, studyInstanceUid).then(function(data) {
-        resolve(data);
-      }, reject);
-    }
-  });
+    RetrieveMetadata(server, studyInstanceUid).then(function(data) {
+      resolve(data)
+    }, reject)
+  })
 
   // Store the promise in cache
-  StudyMetaDataPromises.set(studyInstanceUid, promise);
+  StudyMetaDataPromises.set(studyInstanceUid, promise)
+
+  return promise
+}
 
-  return promise;
+/**
+ * Delete the cached study metadata retrieval promise to ensure that the browser will
+ * re-retrieve the study metadata when it is next requested
+ *
+ * @param {String} studyInstanceUid The UID of the Study to be removed from cache
+ *
+ */
+export function deleteStudyMetadataPromise(studyInstanceUid) {
+  if (StudyMetaDataPromises.has(studyInstanceUid)) {
+    StudyMetaDataPromises.delete(studyInstanceUid)
+  }
 }

src/studies/retrieveStudyMetadata.test.js

@@ -0,0 +1,35 @@
+import { retrieveStudyMetadata } from './retrieveStudyMetadata.js'
+
+const fakeDicomWebServer = {}
+
+// Testing Promises: https://jestjs.io/docs/en/asynchronous#promises
+describe('retrieveStudyMetadata.js', () => {
+  it('throws an exception if no server parameter is provided', () => {
+    const callWithNoServer = () => {
+      retrieveStudyMetadata(null, 'fake-study-instance-uid')
+    }
+
+    expect(callWithNoServer).toThrow(Error)
+  })
+
+  it('throws an exception if no studyInstanceUid parameter is provided', () => {
+    const callWithNoStudyInstanceUid = () => {
+      retrieveStudyMetadata(fakeDicomWebServer, null)
+    }
+
+    expect(callWithNoStudyInstanceUid).toThrow(Error)
+  })
+
+  it('caches and returns the same promise for identical studyInstanceUIDs', () => {
+    const firstPromise = retrieveStudyMetadata(
+      fakeDicomWebServer,
+      'fake-study-instance-uid'
+    )
+    const secondPromise = retrieveStudyMetadata(
+      fakeDicomWebServer,
+      'fake-study-instance-uid'
+    )
+
+    expect(firstPromise).toBe(secondPromise)
+  })
+})