Handle missing logfiles correctly

src/emulator/logs.js

@@ -20,37 +20,35 @@ const path = require('path');
 const readline = require('readline');
 
 function readLogLines (filePath, linesToRead, output) {
- try {
- const parts = path.parse(filePath);
- const files = fs
- .readdirSync(parts.dir)
- .filter((file) => file && file.includes(parts.name));
- files.sort();
+ const parts = path.parse(filePath);
+ const files = fs
+ .readdirSync(parts.dir)
+ .filter((file) => file && file.includes(parts.name));
+ files.sort();
 
- // Here, we naively select the newest log file, even if the user wants to
- // display more lines than are available in the newest log file.
- const rl = readline.createInterface({
- input: fs.createReadStream(path.join(parts.dir, files[files.length - 1])),
- terminal: false
- });
- const lines = [];
- rl
- .on('line', (line) => {
- lines.push(line);
- })
- .on('close', () => {
- lines
- .slice(lines.length - linesToRead)
- .forEach((line) => output(`${line}\n`));
- });
- } catch (err) {
+ // Here, we naively select the newest log file, even if the user wants to
+ // display more lines than are available in the newest log file.
+ const stream = fs.createReadStream(path.join(parts.dir, files[files.length - 1] || ''));
+ stream.on('error', (err) => {
  if (err.code === 'ENOENT') {
  output('');
- return;
  }
+ });
 
- throw err;
- }
+ const rl = readline.createInterface({
+ input: stream,
+ terminal: false
+ });
+ const lines = [];
+ rl
+ .on('line', (line) => {
+ lines.push(line);
+ })
+ .on('close', () => {
+ lines
+ .slice(lines.length - linesToRead)
+ .forEach((line) => output(`${line}\n`));
+ });
 }
 
 module.exports = {