test: stream readableState readingMore state

PR-URL: #9868 Refs: #8685 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Italo A. Casas <[email protected]>

Author: chmln

test/parallel/test-stream-readable-reading-readingMore.js

@@ -0,0 +1,65 @@
+'use strict';
+constcommon=require('../common');
+constassert=require('assert');
+constReadable=require('stream').Readable;
+
+constreadable=newReadable({
+read(size){}
+});
+
+conststate=readable._readableState;
+
+// Starting off with false initially.
+assert.strictEqual(state.reading,false);
+assert.strictEqual(state.readingMore,false);
+
+readable.on('data',common.mustCall((data)=>{
+// while in a flowing state, should try to read more.
+if(state.flowing)
+assert.strictEqual(state.readingMore,true);
+
+// reading as long as we've not ended
+assert.strictEqual(state.reading,!state.ended);
+},2));
+
+functiononStreamEnd(){
+// End of stream; state.reading is false
+// And so should be readingMore.
+assert.strictEqual(state.readingMore,false);
+assert.strictEqual(state.reading,false);
+}
+
+readable.on('readable',common.mustCall(()=>{
+// 'readable' always gets called before 'end'
+// since 'end' hasn't been emitted, more data could be incoming
+assert.strictEqual(state.readingMore,true);
+
+// if the stream has ended, we shouldn't be reading
+assert.strictEqual(state.ended,!state.reading);
+
+if(readable.read()===null)// reached end of stream
+process.nextTick(common.mustCall(onStreamEnd,1));
+},2));
+
+readable.on('end',common.mustCall(onStreamEnd));
+
+readable.push('pushed');
+
+// stop emitting 'data' events
+readable.pause();
+
+// read() should only be called while operating in paused mode
+readable.read(6);
+
+// reading
+assert.strictEqual(state.reading,true);
+assert.strictEqual(state.readingMore,true);
+
+// resume emitting 'data' events
+readable.resume();
+
+// add chunk to front
+readable.unshift('unshifted');
+
+// end
+readable.push(null);