Include strings for scalar values

2 files changed, 48 insertions, 22 deletions

diff --git a/js/src/index.ts b/js/src/index.ts
index 13b1f3b..1563b59 100644
--- a/js/src/index.ts
+++ b/js/src/index.ts
@@ -1,15 +1,20 @@
 import dingbats from "./dingbats";
 
-interface UnicodeScalarValue {
+export interface UnicodeScalarValue {
     codePoint: number;
+    string: string;
 }
 
 const dingbatsByDec: {[key: string]: UnicodeScalarValue} = {};
 const dingbatsByHex: {[key: string]: UnicodeScalarValue} = {};
 
+const fromCodePoint = String.fromCodePoint ? String.fromCodePoint : fromCodePointPolyfill;
+
 for (const dingbat of dingbats) {
+    const codePoint = parseInt(dingbat["Unicode dec"], 10);
     const scalarValue = {
-        codePoint: parseInt(dingbat["Unicode dec"], 10),
+        codePoint: codePoint,
+        string: fromCodePoint(codePoint),
     };
 
     dingbatsByDec[dingbat["Typeface name"] + "_" + dingbat["Dingbat dec"]] = scalarValue;
@@ -27,3 +32,16 @@ export function dec(typeface: string, dec: string): UnicodeScalarValue | undefin
 export function hex(typeface: string, hex: string): UnicodeScalarValue | undefined {
     return dingbatsByHex[typeface + "_" + hex.toUpperCase()];
 }
+
+function fromCodePointPolyfill(codePoint: number) {
+    if (codePoint <= 0xFFFF) {
+        // BMP
+        return String.fromCharCode(codePoint);
+    } else {
+        // Astral
+        // https://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae
+        const highSurrogate = Math.floor((codePoint - 0x10000) / 0x400) + 0xD800;
+        const lowSurrogate = (codePoint - 0x10000) % 0x400 + 0xDC00;
+        return String.fromCharCode(highSurrogate, lowSurrogate);
+    }
+};
diff --git a/js/test/tests.ts b/js/test/tests.ts
index a00b827..68a4bdf 100644
--- a/js/test/tests.ts
+++ b/js/test/tests.ts
@@ -3,41 +3,49 @@ import assert from "assert";
 import * as dingbatToUnicode from "../";
 
 export function canConvertFromDingbatCodePointToUnicode() {
-    const result = dingbatToUnicode.codePoint("Wingdings", 41);
+    const result = dingbatToUnicode.codePoint("Wingdings", 41)!!;
 
-    assert.deepStrictEqual(result, {
-        codePoint: 0x2706,
-    });
+    assert.strictEqual(result.codePoint, 0x2706);
 }
 
 export function canConvertFromDecimalDingbatToUnicode() {
-    const result = dingbatToUnicode.dec("Wingdings", "41");
+    const result = dingbatToUnicode.dec("Wingdings", "41")!!;
 
-    assert.deepStrictEqual(result, {
-        codePoint: 0x2706,
-    });
+    assert.strictEqual(result.codePoint, 0x2706);
 }
 
 export function canConvertFromHexDingbatToUnicode() {
-    const result = dingbatToUnicode.hex("Wingdings", "29");
+    const result = dingbatToUnicode.hex("Wingdings", "29")!!;
 
-    assert.deepStrictEqual(result, {
-        codePoint: 0x2706,
-    });
+    assert.strictEqual(result.codePoint, 0x2706);
 }
 
 export function canConvertFromUppercaseHexDingbatToUnicode() {
-    const result = dingbatToUnicode.hex("Wingdings", "3E");
+    const result = dingbatToUnicode.hex("Wingdings", "3E")!!;
 
-    assert.deepStrictEqual(result, {
-        codePoint: 0x2707,
-    });
+    assert.strictEqual(result.codePoint, 0x2707);
 }
 
 export function canConvertFromLowercaseHexDingbatToUnicode() {
-    const result = dingbatToUnicode.hex("Wingdings", "3e");
+    const result = dingbatToUnicode.hex("Wingdings", "3e")!!;
 
-    assert.deepStrictEqual(result, {
-        codePoint: 0x2707,
-    });
+    assert.strictEqual(result.codePoint, 0x2707);
+}
+
+export function returnedValueIncludesCodePoint() {
+    const result = dingbatToUnicode.hex("Wingdings", "29")!!;
+
+    assert.strictEqual(result.codePoint, 0x2706);
+}
+
+export function whenUnicodeCodePointIsInBmpThenReturnedValueIncludesString() {
+    const result = dingbatToUnicode.hex("Wingdings", "29")!!;
+
+    assert.strictEqual(result.string, "\u2706");
+}
+
+export function whenUnicodeCodePointIsInAstralPlaneThenReturnedValueIncludesString() {
+    const result = dingbatToUnicode.hex("Wingdings", "28")!!;
+
+    assert.strictEqual(result.string, "🕿");
 }