update the options in readme, add option for clearing any logs on err…

…or so there's no memory hogging

README.md

@@ -11,24 +11,15 @@ A Grafana Loki transport for the nodejs logging library Winston.
 This Winston transport is used similarly to other Winston transports. Require winston and define a new LokiTransport() inside its options when creating it.
 
 ### Options
-LokiTransport() takes a Javascript object as an input. These are the options that are available:
-
->`host`
-
-The URL of the Grafana Loki server.
-It should contain everything from the protocol to the port.
-
->`interval`
-
-*optional*
-
-The interval at which the transport sends batched logs to Loki. **In seconds.**
-
->`json`
-
-*optional*
-
-Switch to JSON transport instead of Protobuf.
+LokiTransport() takes a Javascript object as an input. These are the options that are available, __required in bold__:
+
+| **Parameter**    | **Description**                                           | **Example**                      |
+| ---------------- | --------------------------------------------------------- | -------------------------------- |
+| __`host`__       | URL for Grafana Loki                                      | http://localhost:3100            |
+| `interval`       | The interval at which batched logs are sent in seconds    | 30                               |
+| `json`           | Use JSON instead of Protobuf for transport                | true                             |
+| `batching`       | If batching is not used, the logs are sent as they come   | true                             |
+| `clearOnError`   | Discard any logs that result in an error during transport | true                             |
 
 ### Example
 ```js

index.js

@@ -8,7 +8,8 @@ module.exports = class LokiTransport extends Transport {
       host: options.host,
       interval: options.interval,
       json: options.json,
-      batching: options.batching
+      batching: options.batching,
+      clearOnError: options.clearOnError
     })
     options.batching && this.batcher.run()
   }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "winston-loki",
-  "version": "2.1.1",
+  "version": "2.1.2",
   "description": "A Winston transport for Grafana Loki",
   "keywords": [
     "winston",

src/batcher.js

@@ -36,22 +36,22 @@ module.exports = class Batcher {
         logEntry = protoHelpers.createProtoTimestamps(logEntry)
       }
       this.sendBatchToLoki(logEntry)
-      return
-    }
-    if (this.options.json) {
-      this.batch.streams.push(logEntry)
     } else {
-      const { streams } = this.batch
-      logEntry = protoHelpers.createProtoTimestamps(logEntry)
-      const match = streams.findIndex(
-        stream => stream.labels === logEntry.labels
-      )
-      if (match > -1) {
-        logEntry.entries.forEach(entry => {
-          streams[match].entries.push(entry)
-        })
+      if (this.options.json) {
+        this.batch.streams.push(logEntry)
       } else {
-        streams.push(logEntry)
+        const { streams } = this.batch
+        logEntry = protoHelpers.createProtoTimestamps(logEntry)
+        const match = streams.findIndex(
+          stream => stream.labels === logEntry.labels
+        )
+        if (match > -1) {
+          logEntry.entries.forEach(entry => {
+            streams[match].entries.push(entry)
+          })
+        } else {
+          streams.push(logEntry)
+        }
       }
     }
   }
@@ -101,6 +101,7 @@ module.exports = class Batcher {
             resolve()
           })
           .catch(err => {
+            this.options.clearOnError && this.clearBatch()
             reject(err)
           })
       }

test/batcher.json.test.js

@@ -93,6 +93,26 @@ describe('Batcher tests with JSON transport', function () {
     }
     expect(batcher.batch.streams.length).toBe(1)
   })
+  it('Should reject promise and clear batch on unsuccessful send if clearOnError is enabled', async function () {
+    const options = JSON.parse(JSON.stringify(fixtures.options_json))
+    options.clearOnError = true
+    batcher = new Batcher(options)
+
+    const errorObject = {
+      statusCode: 404
+    }
+    got.post.rejects(errorObject)
+    batcher.pushLogEntry(JSON.parse(fixtures.logs_mapped[0]))
+    expect(batcher.batch.streams.length).toBe(1)
+
+    try {
+      await batcher.sendBatchToLoki()
+    } catch (error) {
+      expect(error.statusCode).toBe(404)
+    }
+
+    expect(batcher.batch.streams.length).toBe(0)
+  })
   it('Should fail if the batch is not constructed correctly', async function () {
     const responseObject = {
       statusCode: 200,