Use class syntax and extends keyword instead of util.inherits (#16)

`util.inherits` is now deprecated due to issues with how it sets the prototype chain, see: nodejs/node#4179
AndreasMadsen · Dec 29, 2021 · edb8750 · edb8750
1 parent 7a3c1d7
commit edb8750
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Showing 3 changed files with 40 additions and 33 deletions.
diff --git a/hypothesis/one-data-set.js b/hypothesis/one-data-set.js
@@ -2,17 +2,19 @@
 
 const Distribution = require('distributions').Studentt;
 
-const util = require('util');
 const AbstactStudentT = require('./abstact.js');
 
-function StudentT(data, options) {
-  AbstactStudentT.call(this, options);
+class StudentT extends AbstactStudentT {
 
-  this._df = data.size - 1;
-  this._dist = new Distribution(this._df);
+  constructor(data, options) {
+    super(options);
+    this._df = data.size - 1;
+    this._dist = new Distribution(this._df);
+
+    this._se = Math.sqrt(data.variance / data.size);
+    this._mean = data.mean;
+  }
 
-  this._se = Math.sqrt(data.variance / data.size);
-  this._mean = data.mean;
 }
-util.inherits(StudentT, AbstactStudentT);
+
 module.exports = StudentT;
diff --git a/hypothesis/two-data-set.js b/hypothesis/two-data-set.js
@@ -2,21 +2,24 @@
 
 const Distribution = require('distributions').Studentt;
 
-const util = require('util');
 const AbstactStudentT = require('./abstact.js');
 
-function StudentT(left, right, options) {
-  AbstactStudentT.call(this, options);
+class StudentT extends AbstactStudentT {
+
+  constructor(left, right, options) {
+    super(options);
 
-  this._df = left.size + right.size - 2;
-  this._dist = new Distribution(this._df);
+    this._df = left.size + right.size - 2;
+    this._dist = new Distribution(this._df);
 
-  const commonVariance = ((left.size - 1) * left.variance +
-                          (right.size - 1) * right.variance
-                         ) / this._df;
+    const commonVariance = ((left.size - 1) * left.variance +
+                            (right.size - 1) * right.variance
+                          ) / this._df;
+
+    this._se = Math.sqrt(commonVariance * (1 / left.size + 1 / right.size));
+    this._mean = left.mean - right.mean;
+  }
 
-  this._se = Math.sqrt(commonVariance * (1 / left.size + 1 / right.size));
-  this._mean = left.mean - right.mean;
 }
-util.inherits(StudentT, AbstactStudentT);
+
 module.exports = StudentT;
diff --git a/hypothesis/welch.js b/hypothesis/welch.js
@@ -2,24 +2,26 @@
 
 const Distribution = require('distributions').Studentt;
 
-const util = require('util');
 const AbstactStudentT = require('./abstact.js');
 
-function StudentT(left, right, options) {
-  AbstactStudentT.call(this, options);
+class StudentT extends AbstactStudentT {
+
+  constructor(left, right, options) {
+    super(options);
 
-  const leftSE = left.variance / left.size;
-  const rightSE = right.variance / right.size;
-  const commonVariance = leftSE + rightSE;
+    const leftSE = left.variance / left.size;
+    const rightSE = right.variance / right.size;
+    const commonVariance = leftSE + rightSE;
 
-  this._df = Math.pow(commonVariance, 2) / (
-    Math.pow(leftSE, 2) / (left.size - 1) +
-    Math.pow(rightSE, 2) / (right.size - 1)
-  );
-  this._dist = new Distribution(this._df);
+    this._df = Math.pow(commonVariance, 2) / (
+      Math.pow(leftSE, 2) / (left.size - 1) +
+      Math.pow(rightSE, 2) / (right.size - 1)
+    );
+    this._dist = new Distribution(this._df);
 
-  this._se = Math.sqrt(commonVariance);
-  this._mean = left.mean - right.mean;
+    this._se = Math.sqrt(commonVariance);
+    this._mean = left.mean - right.mean;
+  }
 }
-util.inherits(StudentT, AbstactStudentT);
+
 module.exports = StudentT;