Commit ea71f69c authored by Yuanle Song's avatar Yuanle Song
Browse files

add error handling for number input

parent 6721280e

calc.html

+30 −0
Original line number Diff line number Diff line
@@ -216,6 +216,34 @@ 
	      console.assert(m.numberStack[0] === -9);

	      console.assert(m.numberStack[1] === 29 * 2);

	  };

	  const rpnTestNumberErrorHandling = function () {

	      var m = new fsm.RPNCalculator();

	      m.sendKey("num0");

	      m.sendKey("num0");

	      console.assert(m.currentNumber === "0");



	      m = new fsm.RPNCalculator();

	      m.sendKey("dot");

	      console.assert(m.currentNumber === "0.");

	      m.sendKey("backspace");

	      console.assert(m.currentNumber === "0");

	      m.sendKey("backspace");

	      console.assert(m.currentNumber === "");



	      m = new fsm.RPNCalculator();

	      m.sendKey("num1");

	      m.sendKey("dot");

	      m.sendKey("num2");

	      console.assert(m.currentNumber === "1.2");

	      m.sendKey("dot");    // future dot is ignored and show error.

	      console.assert(m.currentNumber === "1.2");

	      m.sendKey("num3");

	      console.assert(m.currentNumber === "1.23");

	      m.sendKey("dot");

	      console.assert(m.currentNumber === "1.23");

	      m.sendKey("return");

	      console.assert(m.numberStack[0] === 1.23);

	  };



	  /**

	   * run all tests.
@@ -236,6 +264,8 @@ 
	      rpnTestNumberHandling();

	      rpnTestAutoCommitNumber();

	      rpnTestOperator();



	      rpnTestNumberErrorHandling();

	  };



	  // page init

fsm.js

+66 −5
Original line number Diff line number Diff line
@@ -169,14 +169,66 @@ var fsm = function () { 
		return keyName.substring(3);

	    }

	};

	/**

	 * press keyName when existing number string is oldNumberString.

	 * return [newNumberString, errMsg]

	 * errMsg will be null if there is no error.

	 */

	const changeNumberString = function (keyName, oldNumberString) {

	    if (oldNumberString === "0" && keyName === keyNames.num0) {

		return [oldNumberString, "more 0s are ignored"];

	    } else if (oldNumberString === "" && keyName === keyNames.dot) {

		return ["0.", null];

	    } else if (keyName === keyNames.dot && oldNumberString.indexOf(".") !== -1) {

		// Note: do not use indexOf(keyNames.dot) in if condition,

		// because the keyName is dot, not ".".

		return [oldNumberString, "more dots are ignored"];

	    } else {

		return [oldNumberString + numKeyToNumString(keyName), null];

	    }

	};

	const testChangeNumberString = function () {

	    var r = changeNumberString(keyNames.dot, "");

	    console.assert(r[0] === "0.");

	    console.assert(r[1] === null);



	    r = changeNumberString(keyNames.num1, "");

	    console.assert(r[0] === "1");

	    console.assert(r[1] === null);



	    r = changeNumberString(keyNames.num1, "2");

	    console.assert(r[0] === "21");

	    console.assert(r[1] === null);



	    r = changeNumberString(keyNames.num0, "0");

	    console.assert(r[0] === "0");

	    console.assert(r[1] !== null);



	    r = changeNumberString(keyNames.num0, "12");

	    console.assert(r[0] === "120");

	    console.assert(r[1] === null);



	    r = changeNumberString(keyNames.dot, "1.2");

	    console.assert(r[0] === "1.2");

	    console.assert(r[1] !== null);

	};

    	this.sendKey = function (keyName) {

	    var num, num1, num2;

	    var numString, errMsg;

	    var r;



    	    switch (this.currentState) {

    	    case stateIdle:

    		if (isNumberKey(keyName)) {

		    // TODO handle errors and special cases

		    this.currentNumber += numKeyToNumString(keyName);

		    r = changeNumberString(keyName, this.currentNumber);

		    numString = r[0];

		    errMsg = r[1];

		    if (errMsg === null) {

			this.currentNumber = numString;

		    } else {

			this.setErrorMsg(errMsg);

		    }

		    // change state

		    this.currentState = stateWaitingForNumberOrAction;

		} else {

		    switch (keyName) {
@@ -218,8 +270,14 @@ var fsm = function () { 
    		break;

    	    case stateWaitingForNumberOrAction:

    		if (isNumberKey(keyName)) {

		    // TODO handle errors and special cases

		    this.currentNumber += numKeyToNumString(keyName);

		    r = changeNumberString(keyName, this.currentNumber);

		    numString = r[0];

		    errMsg = r[1];

		    if (errMsg === null) {

			this.currentNumber = numString;

		    } else {

			this.setErrorMsg(errMsg);

		    }

		    // keep current state

		} else if (keyName === keyNames['return']) {

		    this.numberStack.push(parseFloat(this.currentNumber));
@@ -229,7 +287,7 @@ var fsm = function () { 
		    if (this.currentNumber.length > 0) {

			this.currentNumber = this.currentNumber.substring(0, this.currentNumber.length - 1);

		    } else {

			setErrorMsg("no digits to delete");

			this.setErrorMsg("no digits to delete");

		    }

		} else if (isOperator(keyName)) {

		    // commit number
@@ -253,6 +311,9 @@ var fsm = function () { 
    	    debug("sendKey " + keyName + ", currentState is " + this.currentState);

    	    return this.currentState;

    	};



	// run all tests;

	testChangeNumberString();

    };



    return {