refactor(web): refactor _kmwCharAt

Author: Joshua Horton

web/src/engine/common/web-utils/src/kmwstring.ts

@@ -384,6 +384,27 @@ export function codeUnitToCodePoint(s: string, codeUnitIndex: number) {
   }
 }
 
+/**
+ * Returns the character at a the code point index passed
+ *
+ * @param  {string}  s      The string
+ * @param  {number}  index  A code point index in the string
+ * @return {string}         The corresponding character
+ */
+export function charAt(s: string, index: number) { // charAtPoint
+  const str = s;
+
+  if(!EXTENSION_ENABLED) {
+    return str.charAt(index);
+  }
+
+  if(index >= 0) {
+    return substr(str, index, 1);
+  } else {
+    return ''
+  };
+}
+
 /*
  * TODO:  Remove this file as part of addressing https://github.com/keymanapp/keyman/issues/2492.
  */
@@ -392,53 +413,18 @@ declare global {
   interface StringConstructor {
     kmwEnableSupplementaryPlane(bEnable: boolean): void
   }
-
-  interface String {
-    kmwCharAt(codePointIndex: number) : string,
-    _kmwCharAt(codePointIndex: number) : string,
-  }
 }
 
 export default function extendString() {
-  /*
-    Helper functions
-  */
-
-  /**
-   * Returns the character at a the code point index passed
-   *
-   * @param  {number}  codePointIndex  A code point index in the string
-   * @return {string}                  The corresponding character
-   */
-  String.prototype.kmwCharAt = function(codePointIndex) {
-    var str = String(this);
-
-    if(codePointIndex >= 0) return substr(str, codePointIndex,1); else return '';
-  }
-
-  /**
-   * String prototype library extensions for basic plane characters,
-   * to simplify enabling or disabling supplementary plane functionality (I3319)
-   */
-
-
   /**
    * Enable or disable supplementary plane string handling
    *
    * @param  {boolean}  bEnable
    */
   String.kmwEnableSupplementaryPlane = function(bEnable)
   {
-    var p=String.prototype;
-    p._kmwCharAt = bEnable ? p.kmwCharAt : p.charAt;
-
     enableSupplementaryPlane(bEnable);
   }
-
-  // Ensure that _all_ String extensions are established, even if disabled by default.
-  if(!""._kmwCharAt) {
-    String.kmwEnableSupplementaryPlane(false);
-  }
 }
 
 // For side-effect imports:

web/src/engine/common/web-utils/src/tests/stringHandling.js

@@ -8,14 +8,14 @@ describe('Unicode string handling', () => {
       String.kmwEnableSupplementaryPlane(false);
     });
 
-    it('_kmwCharAt', () => {
+    it('charAt', () => {
       const str = "string";
-      assert.equal(str._kmwCharAt(-1), '');
-      assert.equal(str._kmwCharAt(6), '');
-      assert.equal(str._kmwCharAt(1000), '');
-      assert.equal(str._kmwCharAt(0), "s");
-      assert.equal(str._kmwCharAt(2), "r");
-      assert.equal(str._kmwCharAt(5), "g");
+      assert.equal(KMWString.charAt(str, -1), '');
+      assert.equal(KMWString.charAt(str, 6), '');
+      assert.equal(KMWString.charAt(str, 1000), '');
+      assert.equal(KMWString.charAt(str, 0), "s");
+      assert.equal(KMWString.charAt(str, 2), "r");
+      assert.equal(KMWString.charAt(str, 5), "g");
     });
 
     it('charCodeAt', () => {
@@ -121,14 +121,14 @@ describe('Unicode string handling', () => {
       String.kmwEnableSupplementaryPlane(true);
     });
 
-    it('_kmwCharAt', () => {
+    it('charAt', () => {
       const str = "string";
-      assert.equal(str._kmwCharAt(-1), '');
-      assert.equal(str._kmwCharAt(6), '');
-      assert.equal(str._kmwCharAt(1000), '');
-      assert.equal(str._kmwCharAt(0), "s");
-      assert.equal(str._kmwCharAt(2), "r");
-      assert.equal(str._kmwCharAt(5), "g");
+      assert.equal(KMWString.charAt(str, -1), '');
+      assert.equal(KMWString.charAt(str, 6), '');
+      assert.equal(KMWString.charAt(str, 1000), '');
+      assert.equal(KMWString.charAt(str, 0), "s");
+      assert.equal(KMWString.charAt(str, 2), "r");
+      assert.equal(KMWString.charAt(str, 5), "g");
     });
 
     it('charCodeAt', () => {
@@ -240,17 +240,17 @@ describe('Unicode string handling', () => {
       String.kmwEnableSupplementaryPlane(true);
     });
 
-    it('_kmwCharAt', () => {
+    it('charAt', () => {
       // 0x1d5c9: MATHEMATICAL SANS-SERIF SMALL p
       // 0x1d5be: MATHEMATICAL SANS-SERIF SMALL e
       const apples = 'a' + String.fromCodePoint(0x1d5c9) + 'p' + 'l' + String.fromCodePoint(0x1d5be) + 's';
-      assert.equal(apples._kmwCharAt(-1), '');
-      assert.equal(apples._kmwCharAt(6), '');
-      assert.equal(apples._kmwCharAt(1000), '');
-      assert.equal(apples._kmwCharAt(0), "a");
-      assert.equal(apples._kmwCharAt(1), String.fromCodePoint(0x1d5c9));
-      assert.equal(apples._kmwCharAt(2), "p");
-      assert.equal(apples._kmwCharAt(5), "s");
+      assert.equal(KMWString.charAt(apples, -1), '');
+      assert.equal(KMWString.charAt(apples, 6), '');
+      assert.equal(KMWString.charAt(apples, 1000), '');
+      assert.equal(KMWString.charAt(apples, 0), "a");
+      assert.equal(KMWString.charAt(apples, 1), String.fromCodePoint(0x1d5c9));
+      assert.equal(KMWString.charAt(apples, 2), "p");
+      assert.equal(KMWString.charAt(apples, 5), "s");
     });
 
     it('charCodeAt', () => {

web/src/engine/js-processor/src/kbdInterface.ts

@@ -643,7 +643,7 @@ export default class KeyboardInterface extends KeyboardHarness {
       // Nope, so let's build its cache.
       var result: ComplexKeyboardStore = [];
       for(var i=0; i < KMWString.length(store); i++) {
-        result.push(store._kmwCharAt(i));
+        result.push(KMWString.charAt(store, i));
       }
 
       // Cache the result for later!

web/src/engine/predictive-text/worker-thread/src/main/correction/context-tracker.ts

@@ -18,7 +18,7 @@ function textToCharTransforms(text: string, transformId?: number) {
   let perCharTransforms: Transform[] = [];
 
   for(let i=0; i < KMWString.length(text); i++) {
-    let char = text.kmwCharAt(i); // is SMP-aware
+    let char = KMWString.charAt(text, i); // is SMP-aware
 
     let transform: Transform = {
       insert: char,