Fix PUTing documents with If-None-Match when non-existent

lib/controllers/storage.js

@@ -33,10 +33,12 @@ class Storage extends Controller {
 
   async get (head = false) {
     const version = this.getVersion();
+    const matchVersion = !!this.request.headers['if-match'];
+
     if (await this.checkToken('r')) {
       let numBytesWritten = 0;
       try {
-        var { item, versionMatch } = await this.server._store.get(this._username, this._path, version, head);
+        var { item, versionMatch } = await this.server._store.get(this._username, this._path, version, matchVersion, head);
       } catch (e) {
         getLogger().error(`Your storage backend does not behave correctly => ${e.message}`);
         this.response.writeHead(500, this._headers);
@@ -59,7 +61,7 @@ class Storage extends Controller {
       }
 
       this.setVersion(item && item.ETag);
-      if (versionMatch) {
+      if (!matchVersion && versionMatch) {
         delete this._headers['Content-Type'];
         this.response.writeHead(304, this._headers);
         this.response.end();
@@ -86,10 +88,14 @@ class Storage extends Controller {
       return false;
     }
     const version = this.getVersion();
+    const matchVersion = !!this.request.headers['if-match'];
+
     let status, error, created, modified, conflict, isDir;
     if (await this.checkToken('w')) {
       try {
-        ({ created, modified, conflict, isDir } = await this.server._store.put(this._username, this._path, type, value, version));
+        ({ created, modified, conflict, isDir } = await this.server._store.put(
+          this._username, this._path, type, value, version, matchVersion
+        ));
         status = conflict
           ? 412
           : isDir

lib/stores/file_tree.js

@@ -198,15 +198,15 @@ class FileTree {
     }
   }
 
-  async put (username, pathname, type, value, version) {
+  async put (username, pathname, type, value, version, matchVersion) {
     const datapath = this.dataPath(username, pathname);
     const metapath = this._metaPath(username, pathname);
     const basename = decodeURI(path.basename(pathname));
     await this._lock(username);
     const metadata = await this.readMeta(username, pathname);
     let created = false;
 
-    if (version) {
+    if (version && matchVersion) {
       if (version === '*'
         // check document existence when version '*' specified
         ? metadata.items && metadata.items[basename]
@@ -217,6 +217,12 @@ class FileTree {
         await this._unlock(username);
         return { conflict: true, created };
       }
+    } else if (version && !matchVersion) {
+      if (metadata.items && metadata.items[basename] &&
+         version.replace(/"/g, '') === metadata.items[basename].ETag) {
+        await this._unlock(username);
+        return { conflict: true, created };
+      }
     }
 
     if (metadata.items[`${basename}/`]) {

spec/store_spec.js

@@ -148,6 +148,54 @@ sharedExamplesFor('Stores', (store) => {
         expect(!conflict).to.be.true;
       });
 
+      it("doesn't set the value of an existing item, when If-Match [ETag] doesn't match", async () => {
+        // client 1
+        const client1put1 = await store.put('boris', '/if-match/no-match', 'text/markdown', Buffer.from('Original paragraph'), null);
+        expect(client1put1.conflict).to.be.false;
+        expect(client1put1.created).to.be.true;
+
+        // both clients
+        const { item: original } = await store.get('boris', '/if-match/no-match', null);
+        expect(original.ETag).to.exist;
+
+        // client 2
+        const client2put = await store.put('boris', '/if-match/no-match', 'text/markdown', Buffer.from('Changed paragraph'), original.ETag);
+        expect(client2put.conflict).to.be.false;
+        expect(client2put.created).to.be.false;
+        const { item: change1 } = await store.get('boris', '/if-match/no-match', null);
+        expect(change1.value.toString('utf8')).to.be.deep.equal('Changed paragraph');
+        expect(change1.ETag).to.not.equal(original.ETag);
+
+        // client 1
+        const client1put2 = await store.put('boris', '/if-match/no-match', 'text/markdown', Buffer.from('Another change'), original.ETag);
+        expect(client1put2.conflict).to.be.true;
+        expect(client1put2.created).to.be.false;
+
+        const { item: final } = await store.get('boris', '/if-match/no-match', null);
+        expect(final.value.toString('utf8')).to.be.deep.equal('Changed paragraph');
+        expect(final.ETag).to.equal(change1.ETag);
+      });
+
+      it("doesn't set the value of an existing item, when If-None-Match * is used", async () => {
+        const response1 = await store.put('boris', '/if-none-match/star', 'text/markdown', Buffer.from('# Some Title'), null);
+        expect(response1.conflict).to.be.false;
+        expect(response1.created).to.be.true;
+        const response2 = await store.put('boris', '/if-none-match/star', 'text/markdown', Buffer.from('# Another Title'), '*');
+        expect(response2.conflict).to.be.true;
+        expect(response2.created).to.be.false;
+        const { item } = await store.get('boris', '/if-none-match/star', null);
+        expect(item.value).to.be.deep.equal(Buffer.from('# Some Title'));
+      });
+
+      it("doesn't set the value of an existing item, when If-None-Match [ETag] matches", async () => {
+        await store.put('boris', '/if-none-match/etag', 'text/markdown', Buffer.from('* Original Item'), null);
+        const { item: original } = await store.get('boris', '/if-none-match/etag', null);
+        expect(original.ETag).to.exist;
+        await store.put('boris', '/if-none-match/etag', 'text/markdown', Buffer.from('* Changed Item'), original.ETag);
+        const { item: final } = await store.get('boris', '/if-none-match/etag', null);
+        expect(final.value.toString('utf8')).to.be.deep.equal('* Original Item');
+      });
+
       describe('for a nested document', () => {
         it('created the parent directory', async () => {
           await store.put('boris', '/photos/foo/bar/qux', 'image/poster', Buffer.from('vertibo'), null);