tail - npm Package Compare versions

Comparing version 2.0.4 to 2.1.0

lib/tail.js

@@ -1,230 +0,207 @@
-// Generated by CoffeeScript 2.4.1
-var Tail, environment, events, fs, path,
-  boundMethodCheck = function(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new Error('Bound instance method accessed before binding'); } };
+let events = require(`events`)
+let fs = require('fs')
+let path = require('path')
 
-events = require("events");
+// const environment = process.env['NODE_ENV'] || 'development'
 
-fs = require('fs');
+class devNull {
+    info() { };
+    error() { };
+};
 
-path = require('path');
+class Tail extends events.EventEmitter {
+        
+    constructor(filename, options = {}) {
+        super();
+        this.filename = filename;
+        this.absPath = path.dirname(this.filename);
+        this.separator = (options.separator !== undefined) ? options.separator : /[\r]{0,1}\n/;// null is a valid param
+        this.fsWatchOptions = options.fsWatchOptions || {};
+        this.follow = options.follow || true;
+        this.logger = options.logger || new devNull();
+        this.useWatchFile = options.useWatchFile || false;
+        this.flushAtEOF = options.flushAtEOF || false;
+        this.encoding = options.encoding || `utf-8`;
+        const fromBeginning = options.fromBeginning || false;
 
-environment = process.env['NODE_ENV'] || 'development';
 
-Tail = class Tail extends events.EventEmitter {
-  readBlock() {
-    var block, stream;
-    boundMethodCheck(this, Tail);
-    if (this.queue.length >= 1) {
-      block = this.queue[0];
-      if (block.end > block.start) {
-        stream = fs.createReadStream(this.filename, {
-          start: block.start,
-          end: block.end - 1,
-          encoding: this.encoding
-        });
-        stream.on('error', (error) => {
-          if (this.logger) {
-            this.logger.error(`Tail error: ${error}`);
-          }
-          return this.emit('error', error);
-        });
-        stream.on('end', () => {
-          var x;
-          x = this.queue.shift();
-          if (this.queue.length > 0) {
-            this.internalDispatcher.emit("next");
-          }
-          if (this.flushAtEOF && this.buffer.length > 0) {
-            this.emit("line", this.buffer);
-            return this.buffer = '';
-          }
-        });
-        return stream.on('data', (data) => {
-          var chunk, i, len, parts, results;
-          if (this.separator === null) {
-            return this.emit("line", data);
-          } else {
-            this.buffer += data;
-            parts = this.buffer.split(this.separator);
-            this.buffer = parts.pop();
-            results = [];
-            for (i = 0, len = parts.length; i < len; i++) {
-              chunk = parts[i];
-              results.push(this.emit("line", chunk));
+        this.logger.info(`Tail starting...`)
+        this.logger.info(`filename: ${this.filename}`);
+        this.logger.info(`encoding: ${this.encoding}`);
+
+        try {
+            fs.accessSync(this.filename, fs.constants.F_OK);
+        } catch (err) {
+            if (err.code == 'ENOENT') {
+                throw err
             }
-            return results;
-          }
+        }
+
+        this.buffer = '';
+        this.internalDispatcher = new events.EventEmitter();
+        this.queue = [];
+        this.isWatching = false;
+
+        // this.internalDispatcher.on('next',this.readBlock);
+        this.internalDispatcher.on('next', () => {
+            this.readBlock();
         });
-      }
+
+        this.logger.info(`fromBeginning: ${fromBeginning}`);
+        let startingPos = undefined;
+        if (fromBeginning) {
+            startingPos = 0;
+            //if fromBeginning triggers a check for content to flush the existing file
+            //without waiting for a new appended line
+            this.change(this.filename);
+        } 
+        this.watch(startingPos);
     }
-  }
 
-  constructor(filename, options = {}) {
-    var err, fromBeginning;
-    super(filename, options);
-    this.readBlock = this.readBlock.bind(this);
-    this.change = this.change.bind(this);
-    this.filename = filename;
-    this.absPath = path.dirname(this.filename);
-    ({separator: this.separator = /[\r]{0,1}\n/, fsWatchOptions: this.fsWatchOptions = {}, follow: this.follow = true, logger: this.logger, useWatchFile: this.useWatchFile = false, flushAtEOF: this.flushAtEOF = false, encoding: this.encoding = "utf-8", fromBeginning = false} = options);
-    if (this.logger) {
-      this.logger.info("Tail starting...");
-      this.logger.info(`filename: ${this.filename}`);
-      this.logger.info(`encoding: ${this.encoding}`);
-      try {
-        fs.accessSync(this.filename, fs.constants.F_OK);
-      } catch (error1) {
-        err = error1;
-        if (err.code === 'ENOENT') {
-          throw err;
+    latestPosition() {
+        try {
+            return fs.statSync(this.filename).size;
+        } catch (err) {
+            this.logger.error(`size check for ${this.filename} failed: ${err}`);
+            this.emit("error", `size check for ${this.filename} failed: ${err}`);
+            throw err;
         }
-      }
     }
-    this.buffer = '';
-    this.internalDispatcher = new events.EventEmitter();
-    this.queue = [];
-    this.isWatching = false;
-    this.internalDispatcher.on('next', () => {
-      return this.readBlock();
-    });
-    this.watch(fromBeginning);
-  }
 
-  change(filename) {
-    var err, stats;
-    boundMethodCheck(this, Tail);
-    try {
-      stats = fs.statSync(filename);
-    } catch (error1) {
-      err = error1;
-      if (this.logger) {
-        this.logger.error(`change event for ${filename} failed: ${err}`);
-      }
-      this.emit("error", `change event for ${filename} failed: ${err}`);
-      return;
+    readBlock() {
+        if (this.queue.length >= 1) {
+            const block = this.queue[0];
+            if (block.end > block.start) {
+                let stream = fs.createReadStream(this.filename, { start: block.start, end: block.end - 1, encoding: this.encoding });
+                stream.on('error', (error) => {
+                    this.logger.error(`Tail error: ${error}`);
+                    this.emit('error', error);
+                });
+                stream.on('end', () => {
+                    let _ = this.queue.shift();
+                    if (this.queue.length > 0) {
+                        this.internalDispatcher.emit('next');
+                    }
+                    if (this.flushAtEOF && this.buffer.length > 0) {
+                        this.emit('line', this.buffer);
+                        this.buffer = "";
+                    }
+                });
+                stream.on('data', (d) => {
+                    if (this.separator === null) {
+                        this.emit("line", d);
+                    } else {
+                        this.buffer += d;
+                        let parts = this.buffer.split(this.separator);
+                        this.buffer = parts.pop();
+                        for (const chunk of parts) {
+                            this.emit("line", chunk);
+                        }
+                    }
+                });
+            }
+        }
     }
-    if (stats.size < this.pos) { //scenario where texts is not appended but it's actually a w+
-      this.pos = stats.size;
-    }
-    if (stats.size > this.pos) {
-      this.queue.push({
-        start: this.pos,
-        end: stats.size
-      });
-      this.pos = stats.size;
-      if (this.queue.length === 1) {
-        return this.internalDispatcher.emit("next");
-      }
-    }
-  }
 
-  watch(fromBeginning) {
-    var err, stats;
-    if (this.isWatching) {
-      return;
+    change(filename) {
+        let p = this.latestPosition()
+        if (p < this.pos) {//scenario where text is not appended but it's actually a w+
+            this.pos = p
+        } else if (p > this.pos) {
+            this.queue.push({ start: this.pos, end: p});
+            this.pos = p
+            if (this.queue.length == 1) {
+                this.internalDispatcher.emit("next");
+            }
+        }
     }
-    if (this.logger) {
-      this.logger.info(`filesystem.watch present? ${fs.watch !== void 0}`);
-      this.logger.info(`useWatchFile: ${this.useWatchFile}`);
-      this.logger.info(`fromBeginning: ${fromBeginning}`);
-    }
-    this.isWatching = true;
-    try {
-      stats = fs.statSync(this.filename);
-    } catch (error1) {
-      err = error1;
-      if (this.logger) {
-        this.logger.error(`watch for ${this.filename} failed: ${err}`);
-      }
-      this.emit("error", `watch for ${this.filename} failed: ${err}`);
-      return;
-    }
-    this.pos = fromBeginning ? 0 : stats.size;
-    if (this.pos === 0) {
-      this.change(this.filename);
-    }
-    if (!this.useWatchFile && fs.watch) {
-      if (this.logger) {
-        this.logger.info("watch strategy: watch");
-      }
-      return this.watcher = fs.watch(this.filename, this.fsWatchOptions, (e, filename) => {
-        return this.watchEvent(e, filename);
-      });
-    } else {
-      if (this.logger) {
-        this.logger.info("watch strategy: watchFile");
-      }
-      return fs.watchFile(this.filename, this.fsWatchOptions, (curr, prev) => {
-        return this.watchFileEvent(curr, prev);
-      });
-    }
-  }
 
-  rename(filename) {
-    //MacOS sometimes throws a rename event for no reason.
-    //Different platforms might behave differently.
-    //see https://nodejs.org/api/fs.html#fs_fs_watch_filename_options_listener
-    //filename might not be present.
-    //https://nodejs.org/api/fs.html#fs_filename_argument
-    //Better solution would be check inode but it will require a timeout and
-    // a sync file read.
-    if (filename === void 0 || filename !== this.filename) {
-      this.unwatch();
-      if (this.follow) {
-        this.filename = path.join(this.absPath, filename);
-        return this.rewatchId = setTimeout((() => {
-          return this.watch();
-        }), 1000);
-      } else {
-        if (this.logger) {
-          this.logger.error(`'rename' event for ${this.filename}. File not available.`);
+    watch(startingPos) {
+        if (this.isWatching) {
+            return
         }
-        return this.emit("error", `'rename' event for ${this.filename}. File not available.`);
-      }
-    } else {
+        this.logger.info(`filesystem.watch present? ${fs.watch != undefined}`);
+        this.logger.info(`useWatchFile: ${this.useWatchFile}`);
 
+        this.isWatching = true;
+        this.pos = (startingPos === undefined) ? this.latestPosition() : startingPos;
+
+        try {
+            if (!this.useWatchFile && fs.watch) {
+                this.logger.info(`watch strategy: watch`);
+                this.watcher = fs.watch(this.filename, this.fsWatchOptions, (e, filename) => { this.watchEvent(e, filename); });
+    
+            } else {
+                this.logger.info(`watch strategy: watchFile`);
+                fs.watchFile(this.filename, this.fsWatchOptions, (curr, prev) => { this.watchFileEvent(curr, prev) });
+            }
+        } catch (err) {
+            this.logger.error(`watch for ${this.filename} failed: ${err}`);
+            this.emit("error", `watch for ${this.filename} failed: ${err}`);
+            return
+        }
     }
-  }
 
-  // @logger.info("rename event but same filename")
-  watchEvent(e, evtFilename) {
-    if (e === 'change') {
-      return this.change(this.filename);
-    } else if (e === 'rename') {
-      return this.rename(evtFilename);
+    rename(filename) {
+        //TODO
+        //MacOS sometimes throws a rename event for no reason.
+        //Different platforms might behave differently.
+        //see https://nodejs.org/api/fs.html#fs_fs_watch_filename_options_listener
+        //filename might not be present.
+        //https://nodejs.org/api/fs.html#fs_filename_argument
+        //Better solution would be check inode but it will require a timeout and
+        // a sync file read.
+        if (filename === undefined || filename !== this.filename) {
+            this.unwatch();
+            if (this.follow) {
+                this.filename = path.join(this.absPath, filename);
+                this.rewatchId = setTimeout((() => { 
+                    this.watch(this.pos); 
+                }), 1000);
+            } else {
+                this.logger.error(`'rename' event for ${this.filename}. File not available anymore.`);
+                this.emit("error", `'rename' event for ${this.filename}. File not available anymore.`);
+            }
+        } else {
+            // this.logger.info("rename event but same filename")
+        }
     }
-  }
 
-  watchFileEvent(curr, prev) {
-    if (curr.size > prev.size) {
-      this.pos = curr.size; // Update @pos so that a consumer can determine if entire file has been handled
-      this.queue.push({
-        start: prev.size,
-        end: curr.size
-      });
-      if (this.queue.length === 1) {
-        return this.internalDispatcher.emit("next");
-      }
+    watchEvent(e, evtFilename) {
+        if (e === 'change') {
+            this.change(this.filename);
+        } else if (e === 'rename') {
+            this.rename(evtFilename);
+        }
     }
-  }
 
-  unwatch() {
-    if (this.watcher) {
-      this.watcher.close();
-    } else {
-      fs.unwatchFile(this.filename);
+    watchFileEvent(curr, prev) {
+        if (curr.size > prev.size) {
+            this.pos = curr.size;    //Update this.pos so that a consumer can determine if entire file has been handled
+            this.queue.push({ start: prev.size, end: curr.size });
+            if (this.queue.length == 1) {
+                this.internalDispatcher.emit("next");
+            }
+        }
     }
-    if (this.rewatchId) {
-      clearTimeout(this.rewatchId);
-      this.rewatchId = void 0;
+
+    unwatch() {
+        if (this.watcher) {
+            this.watcher.close();
+        } else {
+            fs.unwatchFile(this.filename);
+        }
+        if (this.rewatchId) {
+            clearTimeout(this.rewatchId);
+            this.rewatchId = undefined;
+        }
+        this.isWatching = false;
+        this.queue = [];// TODO: is this correct behaviour?
+        if (this.logger) {
+            this.logger.info(`Unwatch ${this.filename}`);
+        }
     }
-    this.isWatching = false;
-    this.queue = [];
-    if (this.logger) {
-      return this.logger.info("Unwatch ", this.filename);
-    }
-  }
 
-};
+}
 
-exports.Tail = Tail;
+exports.Tail = Tail

package.json

@@ -17,3 +17,3 @@ {
   ],
-  "version": "2.0.4",
+  "version": "2.1.0",
   "homepage": "https://www.lucagrulla.com/node-tail",
@@ -29,6 +29,7 @@ "repository": {
   "scripts": {
-    "build": "cake build",
+    "build": "rm -f ./lib/** && cp src/tail.js ./lib/",
     "prepare": "npm run build",
     "prepublishOnly": "npm run test",
-    "test": "mocha"
+    "test": "mocha",
+    "coverage": "nyc npm run test"
   },
@@ -38,6 +39,6 @@ "license": "MIT",
   "devDependencies": {
-    "coffeescript": "2.5.1",
     "chai": "4.x",
-    "mocha": "7.x"
+    "mocha": "8.x",
+    "nyc": "^15.1.0"
   }
 }

README.md

@@ -108,9 +108,8 @@ # Tail
 
-Tail is written in [CoffeeScript](https://coffeescript.org/).
+Tail is written in plain ES6.Pull Requests are welcome.
 
-The Cakefile generates the javascript that is then published to npm.
-
 ## History
 
 Tail was born as part of a data firehose. Read about it [here](https://www.lucagrulla.com/posts/building-a-firehose-with-nodejs/).
+Tail original version was written in [CoffeeScript](https://coffeescript.org/). Since 2020 it's pure ES6.
 
@@ -117,0 +116,0 @@ ## License

New alerts

License Policy Violation

License

This package is not allowed per your license policy. Review the package's license to ensure compliance.

Found 1 instance in 1 package

Major refactor

Supply chain risk

Package has recently undergone a major refactor. It may be unstable or indicate significant internal changes. Use caution when updating to versions that include significant changes.

Found 1 instance in 1 package

Dynamic require

Supply chain risk

Dynamic require can indicate the package is performing dangerous or unsafe dynamic code execution.

Found 1 instance in 1 package

Fixed alerts

License Policy Violation

License

This package is not allowed per your license policy. Review the package's license to ensure compliance.

Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

9916356

increased by79684.02%

Number of package files

19

increased by216.67%

Lines of code

470

increased by116.59%

Worsened metrics

Number of lines in readme file

118

decreased by-0.84%

Number of low supply chain risk alerts

4

increased by100%

Number of medium supply chain risk alerts

1

increased byInfinity%

No dependency changes