📝 Add docstrings to code-test

main.ts

@@ -1,3 +1,14 @@
+/**
+ * Performs a basic arithmetic operation on two numbers.
+ *
+ * This function applies the operator ("+", "-", "*", or "/") to the given operands and
+ * returns the computed result.
+ *
+ * @param firstNumber - The first operand.
+ * @param secondNumber - The second operand.
+ * @param operator - The arithmetic operator to use; valid values are "+", "-", "*", or "/".
+ * @returns The result of performing the arithmetic operation.
+ */
 function solve(firstNumber: number, secondNumber: number, operator: string): number {
     const operations: { [index: string]: Function } = {
         "+": () => firstNumber + secondNumber,
@@ -10,6 +21,16 @@ function solve(firstNumber: number, secondNumber: number, operator: string): num
 }
 
 
+/**
+ * Evaluates a simple sub-expression using the two most recent numeric operands and the last operator.
+ *
+ * This function removes the last two elements from the output array, converts them to numbers, retrieves the last operator from the operators array, and calculates the result using the `solve` function. The computed result is pushed back onto the output array as a string.
+ *
+ * @param output - An array of strings representing numeric operands, with the last two entries serving as operands.
+ * @param operators - An array of strings representing operators, where the last entry is used for the calculation.
+ *
+ * @throws {string} "Operation Not Supported." if no operator is available.
+ */
 function solveSimplifiedExpr(output: Array<string>, operators: Array<string>): void {
     const secondNumber = Number(output.pop());
     const firstNumber = Number(output.pop());
@@ -23,12 +44,32 @@ function solveSimplifiedExpr(output: Array<string>, operators: Array<string>): v
     output.push(solve(firstNumber, secondNumber, operator).toString());
 }
 
+/**
+ * Checks if the provided character is a digit (0-9).
+ *
+ * @param character The character to evaluate.
+ * @returns True if the character is a digit, false otherwise.
+ */
 function isDigit(character: string) {
     return character.charCodeAt(0) >= "0".charCodeAt(0)
         && character.charCodeAt(0) <= "9".charCodeAt(0);
 }
 
 
+/**
+ * Parses a mathematical expression string into an array of tokens.
+ *
+ * The function tokenizes the expression by removing all spaces and then separating numbers,
+ * decimal points, arithmetic operators, and parentheses. It supports negative numbers
+ * and validates proper decimal formatting, operator positioning, and balanced parentheses.
+ * If the expression is malformed, it throws an error with a descriptive message.
+ *
+ * @param expression - The mathematical expression to parse.
+ * @returns An array of tokens representing numbers, operators, and parentheses.
+ *
+ * @throws {string} When a decimal number is malformed, an operator is misplaced,
+ *                  a parenthesis is unmatched, or an invalid character is encountered.
+ */
 function parseExpression(expression: string) {
     const operators: Array<string> = ["+", "-", "*", "/"];
     const expr: Array<string> = [];
@@ -96,6 +137,18 @@ function parseExpression(expression: string) {
     return expr;
 }
 
+/**
+ * Evaluates a mathematical expression string and returns its numerical result.
+ *
+ * The function tokenizes the input using `parseExpression` and then evaluates the expression 
+ * using a stack-based algorithm that respects operator precedence and handles parentheses.
+ * Intermediate results are computed by repeatedly applying operations via `solveSimplifiedExpr`.
+ *
+ * @param expression - The mathematical expression to evaluate.
+ * @returns The numerical result of the evaluated expression.
+ *
+ * @throws Error if the expression is malformed, such as having unmatched parentheses or invalid tokens.
+ */
 function solveExpression(expression: string) {
     const priorities: { [index: string]: number } = {
         "+": 1,