Creating regex for our generators which will allow the bot to au… (#1639)

* WIP: creating regex for our generators which will allow the bot to automatically label issues and PRs

* Include additional WIP regex

* Remainder of implemented generators

* Add tests for regex in auto labeling

Author: jimschubert

.github/.test/auto-labeler.js

@@ -0,0 +1,117 @@
+let fs   = require('fs');
+let path = require('path');
+let util = require('util');
+let yaml = require('./js-yaml.js');
+let samples = require('./samples.json');
+
+class LabelMatch {
+    constructor (match, label) {
+        this.match = match;
+        this.label = label;
+    }
+}
+
+class FileError {
+    constructor (file, actualLabels, expectedLabels) {
+        this.file = file;
+        this.actual = actualLabels;
+        this.expected = expectedLabels;
+    }
+}
+
+class TextError {
+    constructor (text, actualLabels, expectedLabels) {
+        this.text = text;
+        this.actual = actualLabels;
+        this.expected = expectedLabels;
+    }
+}
+
+let labels = [];
+
+function labelsForFile(file) {
+    let body = fs.readFileSync(file);
+    return labelsForText(body)
+}
+
+function labelsForText(text) {
+    let addLabels = new Set();
+    let body = text;
+    for (const v of labels) {
+        if (v.match.test(body)) {
+            addLabels.add(v.label)
+        }
+        // reset regex state
+        v.match.lastIndex = 0
+    }
+    return addLabels;
+}
+
+try {
+    let config = yaml.safeLoad(fs.readFileSync('../auto-labeler.yml', 'utf8'));
+
+    if (config && config.labels && Object.keys(config.labels).length > 0) {
+        for (const labelName in config.labels) {
+            if (config.labels.hasOwnProperty(labelName)) {
+                let matchAgainst = config.labels[labelName];
+                if (Array.isArray(matchAgainst)) {
+                    matchAgainst.forEach(regex => {
+                        // noinspection JSCheckFunctionSignatures
+                        labels.push(new LabelMatch(new RegExp(regex, 'g'), labelName));
+                    })
+                }
+            }
+        }
+    }
+
+    if (labels.length === 0) {
+        // noinspection ExceptionCaughtLocallyJS
+        throw new Error("Expected to parse config.labels, but failed.")
+    }
+
+    let fileErrors = [];
+    samples.files.forEach(function(tester){
+        let file = path.normalize(path.join('..', '..', 'bin', tester.input));
+        let expectedLabels = new Set(tester.matches);
+        let actualLabels = labelsForFile(file);
+        let difference = new Set([...actualLabels].filter(x => !expectedLabels.has(x)));
+        if (difference.size > 0) {
+            fileErrors.push(new FileError(file, actualLabels, expectedLabels));
+        }
+    });
+
+    let textErrors = [];
+    samples.text.forEach(function(tester){
+        let expectedLabels = new Set(tester.matches);
+        let actualLabels = labelsForText(tester.input);
+        let difference = new Set([...actualLabels].filter(x => !expectedLabels.has(x)));
+        if (difference.size > 0) {
+            textErrors.push(new TextError(tester.input, actualLabels, expectedLabels));
+        }
+    });
+
+    // These are separate (file vs text) in case we want to preview where these would fail in the file. not priority at the moment.
+    if (fileErrors.length > 0) {
+        console.warn('There were %d file tester errors', fileErrors.length);
+        fileErrors.forEach(function(errs) {
+            console.log("file: %j\n  actual: %j\n  expected: %j", errs.file, util.inspect(errs.actual), util.inspect(errs.expected))
+        });
+    }
+
+    if (textErrors.length > 0) {
+        console.warn('There were %d text tester errors', textErrors.length);
+        textErrors.forEach(function(errs){
+            console.log("input: %j\n  actual: %j\n  expected: %j", errs.text, util.inspect(errs.actual), util.inspect(errs.expected))
+        })
+    }
+
+    let totalErrors = fileErrors.length + textErrors.length;
+    if (totalErrors === 0) {
+        console.log('Success!');
+    } else {
+        console.log('Failure: %d total errors', totalErrors);
+    }
+} catch (e) {
+    console.log(e);
+}
+