Added parseMoney function and test for #35

frontend/src/utils/parseMoney.js

+/**
+ * Function to get a regex object for money parsing
+ *
+ * @returns
+ */
+function getMoneyRegex() {
+  return /:(\d*[.,]?\d*)(\w{3}):/g;
+}
+
+
+
+/**
+ * Parses a string to determine if there are some currency in it.
+ *
+ * For example, the string: "Hi, I earn :10.15CHF:" will be converted to:
+ * [{ isMoney: false, text: 'Hi, I earn ' },
+ * { isMoney: true, amount: '10.15', currency: 'CHF' }]
+ *
+ * In the string: amount can be an int, a float with ',' or '.' as separator
+ *  And the currency can be in mixed case, but will always be return in uppercase.
+ *
+ * @export
+ * @param {string} str
+ * @returns {Array}
+ */
+export default function parseMoney(str) {
+  if (str === "") {
+    return [];
+  }
+
+  // reusable function
+  const getOutputText = (str) => ({ isMoney: false, text: str });
+
+  if (!getMoneyRegex().test(str)) {
+    // if the string doesn't contain anything interesting
+    return [getOutputText(str)];
+  } else {
+
+    let matches = [],
+      match,
+      moneyRegEx = getMoneyRegex();
+
+    while ((match = moneyRegEx.exec(str)) !== null) {
+      const matchStartIndex = match.index, // index of the starting ':'
+        matchLastIndex = moneyRegEx.lastIndex - 1, // index of the ending ':'
+        amount = parseFloat(match["1"].replace(",", ".")), // fix numbers with "," as decimal separators
+        currency = match["2"].toUpperCase(); // make sure the currency is uppercase
+
+      matches.push({ matchStartIndex, matchLastIndex, amount, currency });
+    }
+
+    let res = [], lastIndex = 0;
+
+    matches.forEach((el) => {
+      if (lastIndex !== el.matchStartIndex) {
+        // we need to add a classic string that was before the currency marker
+        res.push(getOutputText(str.substring(lastIndex, el.matchStartIndex)));
+      }
+      // We add the element corresponding to money mount
+      res.push({ isMoney: true, amount: el.amount, currency: el.currency });
+      lastIndex = el.matchLastIndex + 1;
+    });
+
+    // we need to add the eventual trailing text:
+    if (lastIndex !== str.length) {
+      res.push(getOutputText(str.substring(lastIndex)));
+    }
+
+    return res;
+  }
+
+}
+

frontend/tests/utils/parseMoney.test.js

+import parseMoney from "../../src/utils/parseMoney";
+
+test("parse empty string", () => {
+  const str = "";
+  expect(parseMoney(str).length).toBe(0);
+});
+
+test("Parse string with no money", () => {
+  const str = "A random classic string";
+  expect(parseMoney(str).length).toBe(1);
+  expect(parseMoney(str)[0].text).toBe(str);
+});
+
+test("Parse string with only money", () => {
+  const str = ":100CHF:",
+    parsed = parseMoney(str);
+  expect(parsed.length).toBe(1);
+  expect(parsed[0].amount).toBe(100);
+  expect(parsed[0].currency).toBe("CHF");
+});
+
+test("Parse complicated string", () => {
+  const str = "Hi, I earn :0,0Chf: but he earned :100.12EUR: this year !",
+    parsed = parseMoney(str);
+
+  expect(parsed.length).toBe(5);
+
+  expect(parsed[0].isMoney).toBe(false);
+  expect(parsed[1].isMoney).toBe(true);
+  expect(parsed[2].isMoney).toBe(false);
+  expect(parsed[3].isMoney).toBe(true);
+  expect(parsed[4].isMoney).toBe(false);
+
+  expect(parsed[0].text).toBe("Hi, I earn ");
+  expect(parsed[2].text).toBe(" but he earned ");
+  expect(parsed[4].text).toBe(" this year !");
+
+  expect(parsed[1].amount).toBe(0);
+  expect(parsed[3].amount).toBe(100.12);
+
+  expect(parsed[1].currency).toBe("CHF");
+  expect(parsed[3].currency).toBe("EUR");
+});