var -> const using eslint auto fix, phetsims/tasks#1012

js/photon-absorption/model/Molecule.js

@@ -25,16 +25,16 @@ define( require => {
   const Vector2Property = require( 'DOT/Vector2Property' );
 
   // constants
-  var PHOTON_EMISSION_SPEED = 3000; // Picometers per second.
-  var PHOTON_ABSORPTION_DISTANCE = 100; // Distance where the molecule begins to query photon for absorption.
-  var VIBRATION_FREQUENCY = 5;  // Cycles per second of sim time.
-  var ROTATION_RATE = 1.1;  // Revolutions per second of sim time.
-  var ABSORPTION_HYSTERESIS_TIME = 0.2; // seconds
-  var PASS_THROUGH_PHOTON_LIST_SIZE = 10; // Size of list which tracks photons not absorbed due to random probability.
+  const PHOTON_EMISSION_SPEED = 3000; // Picometers per second.
+  const PHOTON_ABSORPTION_DISTANCE = 100; // Distance where the molecule begins to query photon for absorption.
+  const VIBRATION_FREQUENCY = 5;  // Cycles per second of sim time.
+  const ROTATION_RATE = 1.1;  // Revolutions per second of sim time.
+  const ABSORPTION_HYSTERESIS_TIME = 0.2; // seconds
+  const PASS_THROUGH_PHOTON_LIST_SIZE = 10; // Size of list which tracks photons not absorbed due to random probability.
 
   // utility method used for serialization
   function serializeArray( array ) {
-    var serializedArray = [];
+    const serializedArray = [];
     array.forEach( function( arrayElement ) {
       serializedArray.push( arrayElement.toStateObject() );
     } );
@@ -43,7 +43,7 @@ define( require => {
 
   // utility method for finding atom with the specified ID in a list
   function findAtomWithID( atomArray, id ) {
-    for ( var i = 0; i < atomArray.length; i++ ) {
+    for ( let i = 0; i < atomArray.length; i++ ) {
       if ( atomArray[ i ].uniqueID === id ) {
         return atomArray[ i ];
       }
@@ -263,7 +263,7 @@ define( require => {
       }
 
       if ( this.rotatingProperty.get() ) {
-        var directionMultiplier = this.rotationDirectionClockwiseProperty.get() ? -1 : 1;
+        const directionMultiplier = this.rotationDirectionClockwiseProperty.get() ? -1 : 1;
         this.rotate( dt * ROTATION_RATE * 2 * Math.PI * directionMultiplier );
       }
 
@@ -406,15 +406,15 @@ define( require => {
      **/
     queryAbsorbPhoton: function( photon ) {
 
-      var absorbPhoton = false;
+      let absorbPhoton = false;
 
       if ( !this.isPhotonAbsorbed() &&
            this.absorptionHysteresisCountdownTime <= 0 &&
            photon.locationProperty.get().distance( this.getCenterOfGravityPos() ) < PHOTON_ABSORPTION_DISTANCE && !this.isPhotonMarkedForPassThrough( photon ) ) {
 
         // The circumstances for absorption are correct, but do we have an absorption strategy for this photon's
         // wavelength?
-        var candidateAbsorptionStrategy = this.mapWavelengthToAbsorptionStrategy[ photon.wavelength ];
+        const candidateAbsorptionStrategy = this.mapWavelengthToAbsorptionStrategy[ photon.wavelength ];
         if ( typeof candidateAbsorptionStrategy !== 'undefined' ) {
           // Yes, there is a strategy available for this wavelength.
           // Ask it if it wants the photon.
@@ -462,11 +462,11 @@ define( require => {
      * @param {number} wavelength - The photon to be emitted.
      **/
     emitPhoton: function( wavelength ) {
-      var photonToEmit = new Photon( wavelength, this.photonGroupTandem.createNextTandem() );
-      var emissionAngle = phet.joist.random.nextDouble() * Math.PI * 2;
+      const photonToEmit = new Photon( wavelength, this.photonGroupTandem.createNextTandem() );
+      const emissionAngle = phet.joist.random.nextDouble() * Math.PI * 2;
       photonToEmit.setVelocity( PHOTON_EMISSION_SPEED * Math.cos( emissionAngle ),
         ( PHOTON_EMISSION_SPEED * Math.sin( emissionAngle ) ) );
-      var centerOfGravityPosRef = this.centerOfGravityProperty.get();
+      const centerOfGravityPosRef = this.centerOfGravityProperty.get();
       photonToEmit.location = new Vector2( centerOfGravityPosRef.x, centerOfGravityPosRef.y );
       this.absorptionHysteresisCountdownTime = ABSORPTION_HYSTERESIS_TIME;
       this.photonEmittedEmitter.emit( photonToEmit );
@@ -479,9 +479,9 @@ define( require => {
      **/
     updateAtomPositions: function() {
 
-      for ( var uniqueID in this.initialAtomCogOffsets ) {
+      for ( const uniqueID in this.initialAtomCogOffsets ) {
         if ( this.initialAtomCogOffsets.hasOwnProperty( uniqueID ) ) {
-          var atomOffset = new Vector2( this.initialAtomCogOffsets[ uniqueID ].x, this.initialAtomCogOffsets[ uniqueID ].y );
+          const atomOffset = new Vector2( this.initialAtomCogOffsets[ uniqueID ].x, this.initialAtomCogOffsets[ uniqueID ].y );
           // Add the vibration, if any exists.
           atomOffset.add( this.vibrationAtomOffsets[ uniqueID ] );
           // Rotate.
@@ -522,7 +522,7 @@ define( require => {
     fromStateObject: function( stateObject ) {
 
       // Create a molecule that is basically blank.
-      var molecule = new Molecule();
+      const molecule = new Molecule();
 
       // Fill in the straightforward stuff
       molecule.highElectronicEnergyStateProperty.set( stateObject.highElectronicEnergyState );
@@ -537,8 +537,8 @@ define( require => {
 
       // add the bonds
       stateObject.atomicBonds.forEach( function( bondStateObject ) {
-        var atom1 = findAtomWithID( molecule.atoms, bondStateObject.atom1ID );
-        var atom2 = findAtomWithID( molecule.atoms, bondStateObject.atom2ID );
+        const atom1 = findAtomWithID( molecule.atoms, bondStateObject.atom1ID );
+        const atom2 = findAtomWithID( molecule.atoms, bondStateObject.atom2ID );
         assert && assert( atom1 && atom2, 'Error: Couldn\'t match atom ID in bond with atoms in molecule' );
         molecule.addAtomicBond( new AtomicBond( atom1, atom2, { bondCount: bondStateObject.bondCount } ) );
       } );

js/photon-absorption/model/PhotonAbsorptionModel.js

@@ -49,20 +49,20 @@ define( require => {
   // ------- constants -------------
 
   // constants that control where and how photons are emitted.
-  var PHOTON_EMISSION_LOCATION = new Vector2( -2000, 0 );
+  const PHOTON_EMISSION_LOCATION = new Vector2( -2000, 0 );
 
   // Velocity of emitted photons.  Since they are emitted horizontally, only one value is needed.
-  var PHOTON_VELOCITY = 3000; // picometers/second
+  const PHOTON_VELOCITY = 3000; // picometers/second
 
   // Defaults for photon emission periods.
-  var DEFAULT_PHOTON_EMISSION_PERIOD = Number.POSITIVE_INFINITY; // Milliseconds of sim time.
+  const DEFAULT_PHOTON_EMISSION_PERIOD = Number.POSITIVE_INFINITY; // Milliseconds of sim time.
 
   // Default values for various parameters that weren't already covered.
-  var DEFAULT_EMITTED_PHOTON_WAVELENGTH = WavelengthConstants.IR_WAVELENGTH;
-  var INITIAL_COUNTDOWN_WHEN_EMISSION_ENABLED = 0.3; // seconds
+  const DEFAULT_EMITTED_PHOTON_WAVELENGTH = WavelengthConstants.IR_WAVELENGTH;
+  const INITIAL_COUNTDOWN_WHEN_EMISSION_ENABLED = 0.3; // seconds
 
   // Minimum for photon emission periods.
-  var MIN_PHOTON_EMISSION_PERIOD_SINGLE_TARGET = 0.4; // seconds
+  const MIN_PHOTON_EMISSION_PERIOD_SINGLE_TARGET = 0.4; // seconds
 
   /**
    * Constructor for a photon absorption model.
@@ -73,7 +73,7 @@ define( require => {
    */
   function PhotonAbsorptionModel( initialPhotonTarget, tandem ) {
 
-    var self = this;
+    const self = this;
 
     this.photonAbsorptionModel = tandem; // @private
 
@@ -132,7 +132,7 @@ define( require => {
         self.setPhotonEmissionPeriod( Number.POSITIVE_INFINITY );
       }
       else {
-        var singleTargetPeriodFrequency = self.getSingleTargetPeriodFromFrequency( emissionFrequency );
+        const singleTargetPeriodFrequency = self.getSingleTargetPeriodFromFrequency( emissionFrequency );
         self.setPhotonEmissionPeriod( singleTargetPeriodFrequency );
       }
     } );
@@ -161,7 +161,7 @@ define( require => {
       this.photons.clear();
 
       // Reset all active molecules, which will stop any vibrations.
-      for ( var molecule = 0; molecule < this.activeMolecules.length; molecule++ ) {
+      for ( let molecule = 0; molecule < this.activeMolecules.length; molecule++ ) {
         this.activeMolecules.get( molecule ).reset();
       }
 
@@ -227,8 +227,8 @@ define( require => {
      * @param {number} dt - the incremental times step, in seconds
      */
     stepPhotons: function( dt ) {
-      var self = this;
-      var photonsToRemove = [];
+      const self = this;
+      const photonsToRemove = [];
 
       // check for possible interaction between each photon and molecule
       this.photons.forEach( function( photon ) {
@@ -243,13 +243,13 @@ define( require => {
 
       // Remove any photons that were marked for removal.
       this.photons.removeAll( photonsToRemove );
-      for ( var i = 0; i < photonsToRemove.length; i++ ) {
+      for ( let i = 0; i < photonsToRemove.length; i++ ) {
         photonsToRemove[ i ].dispose();
       }
     },
 
     clearPhotons: function() {
-      for ( var i = 0; i < this.photons.length; i++ ) {
+      for ( let i = 0; i < this.photons.length; i++ ) {
         this.photons.get( i ).dispose();
       }
       this.photons.clear();
@@ -261,8 +261,8 @@ define( require => {
      * @param {number} dt - The incremental time step.
      */
     stepMolecules: function( dt ) {
-      var moleculesToStep = this.activeMolecules.getArray().slice( 0 );
-      for ( var molecule = 0; molecule < moleculesToStep.length; molecule++ ) {
+      const moleculesToStep = this.activeMolecules.getArray().slice( 0 );
+      for ( let molecule = 0; molecule < moleculesToStep.length; molecule++ ) {
         moleculesToStep[ molecule ].step( dt );
       }
     },
@@ -290,9 +290,9 @@ define( require => {
      * frames.
      */
     emitPhoton: function( advanceAmount ) {
-      var photon = new Photon( this.photonWavelengthProperty.get(), this.photonGroupTandem.createNextTandem() );
+      const photon = new Photon( this.photonWavelengthProperty.get(), this.photonGroupTandem.createNextTandem() );
       photon.locationProperty.set( new Vector2( PHOTON_EMISSION_LOCATION.x + PHOTON_VELOCITY * advanceAmount, PHOTON_EMISSION_LOCATION.y ) );
-      var emissionAngle = 0; // Straight to the right.
+      const emissionAngle = 0; // Straight to the right.
       photon.setVelocity( PHOTON_VELOCITY * Math.cos( emissionAngle ), PHOTON_VELOCITY * Math.sin( emissionAngle ) );
       this.photons.add( photon );
     },
@@ -374,15 +374,15 @@ define( require => {
      */
     updateActiveMolecule: function( photonTarget, tandem ) {
 
-      var self = this;
+      const self = this;
 
       this.activeMolecules.forEach( function( molecule ) { molecule.dispose(); } );
 
       // Remove the old photon target(s).
       this.activeMolecules.clear(); // Clear the old active molecules array
 
       // Add the new photon target(s).
-      var newMolecule =
+      const newMolecule =
         photonTarget === PhotonTarget.SINGLE_CO_MOLECULE ? new CO( { tandem: tandem.createTandem( 'CO' ) } ) :
         photonTarget === PhotonTarget.SINGLE_CO2_MOLECULE ? new CO2( { tandem: tandem.createTandem( 'CO2' ) } ) :
         photonTarget === PhotonTarget.SINGLE_H2O_MOLECULE ? new H2O( { tandem: tandem.createTandem( 'H2O' ) } ) :
@@ -430,7 +430,7 @@ define( require => {
      * in cases where an atom has broken apart and needs to be restored to its original condition.
      */
     restoreActiveMolecule: function() {
-      var currentTarget = this.photonTargetProperty.get();
+      const currentTarget = this.photonTargetProperty.get();
       this.updateActiveMolecule( currentTarget, this.photonAbsorptionModel );
     }
   } );

js/photon-absorption/model/PhotonAbsorptionModelIO.js

@@ -31,9 +31,9 @@ define( require => {
      */
     static addChildInstance( photonAbsorptionModel, tandem, stateObject ) {
       validate( photonAbsorptionModel, this.validator );
-      var value = PhotonIO.fromStateObject( stateObject );
+      const value = PhotonIO.fromStateObject( stateObject );
 
-      var photon = new phet.moleculesAndLight.Photon( value.wavelength, tandem );
+      const photon = new phet.moleculesAndLight.Photon( value.wavelength, tandem );
       photon.setVelocity( stateObject.vx, stateObject.vy );
       photonAbsorptionModel.photons.add( photon );
     }

js/photon-absorption/model/PhotonAbsorptionStrategy.js

@@ -21,8 +21,8 @@ define( require => {
   const moleculesAndLight = require( 'MOLECULES_AND_LIGHT/moleculesAndLight' );
   const Property = require( 'AXON/Property' );
 
-  var MIN_PHOTON_HOLD_TIME = 0.6; // seconds of sim time
-  var MAX_PHOTON_HOLD_TIME = 1.2; // seconds of sim time
+  const MIN_PHOTON_HOLD_TIME = 0.6; // seconds of sim time
+  const MAX_PHOTON_HOLD_TIME = 1.2; // seconds of sim time
 
   /**
    * Constructor for photon absorption strategy.
@@ -65,7 +65,7 @@ define( require => {
     queryAndAbsorbPhoton: function( photon ) {
       // All circumstances are correct for photon absorption, so now we decide probabilistically whether or not to
       // actually do it.  This essentially simulates the quantum nature of the absorption.
-      var absorbed = (!this.isPhotonAbsorbed) && ( phet.joist.random.nextDouble() < this.photonAbsorptionProbabilityProperty.get() );
+      const absorbed = (!this.isPhotonAbsorbed) && ( phet.joist.random.nextDouble() < this.photonAbsorptionProbabilityProperty.get() );
       if ( absorbed ) {
         this.isPhotonAbsorbed = true;
         this.photonHoldCountdownTime = MIN_PHOTON_HOLD_TIME + phet.joist.random.nextDouble() * ( MAX_PHOTON_HOLD_TIME - MIN_PHOTON_HOLD_TIME );

js/photon-absorption/model/PhotonHoldStrategy.js

@@ -67,7 +67,7 @@ define( require => {
      **/
     queryAndAbsorbPhoton: function( photon ) {
 
-      var absorbed = PhotonAbsorptionStrategy.prototype.queryAndAbsorbPhoton.call( this, photon );
+      const absorbed = PhotonAbsorptionStrategy.prototype.queryAndAbsorbPhoton.call( this, photon );
       if ( absorbed ) {
         this.absorbedWavelength = photon.wavelength;
         this.photonAbsorbed();

js/photon-absorption/model/RotationStrategy.js

@@ -14,7 +14,7 @@ define( require => {
   const PhotonHoldStrategy = require( 'MOLECULES_AND_LIGHT/photon-absorption/model/PhotonHoldStrategy' );
 
   //Random boolean generator.
-  var RAND = {
+  const RAND = {
     nextBoolean: function() {
       return phet.joist.random.nextDouble() < 0.50;
     }

js/photon-absorption/model/WavelengthConstants.js

@@ -18,7 +18,7 @@ define( require => {
   const quadWavelengthSelectorUltravioletString = require( 'string!MOLECULES_AND_LIGHT/QuadWavelengthSelector.Ultraviolet' );
   const quadWavelengthSelectorVisibleString = require( 'string!MOLECULES_AND_LIGHT/QuadWavelengthSelector.Visible' );
 
-  var WavelengthConstants = {
+  const WavelengthConstants = {
 
     // all values in meters
     SUNLIGHT_WAVELENGTH: 400E-9, // Ported from the original JAVA version, but not used in Molecules And Light

js/photon-absorption/model/atoms/Atom.js

@@ -18,7 +18,7 @@ define( require => {
   const PhetColorScheme = require( 'SCENERY_PHET/PhetColorScheme' );
 
   // Static data
-  var instanceCount = 0; // Base count for the unique ID of this atom.
+  let instanceCount = 0; // Base count for the unique ID of this atom.
 
   /**
    * Constructor for creating an individual atom.  This is generally invoked using factory methods for specify atoms.

js/photon-absorption/model/molecules/CH4.js

@@ -21,15 +21,15 @@ define( require => {
   const WavelengthConstants = require( 'MOLECULES_AND_LIGHT/photon-absorption/model/WavelengthConstants' );
 
   // Model Data for Methane
-  var INITIAL_CARBON_HYDROGEN_DISTANCE = 170; // In picometers.
+  const INITIAL_CARBON_HYDROGEN_DISTANCE = 170; // In picometers.
 
   // Assume that the angle from the carbon to the hydrogen is 45 degrees.
-  var ROTATED_INITIAL_CARBON_HYDROGEN_DISTANCE = INITIAL_CARBON_HYDROGEN_DISTANCE * Math.sin( Math.PI / 4 );
+  const ROTATED_INITIAL_CARBON_HYDROGEN_DISTANCE = INITIAL_CARBON_HYDROGEN_DISTANCE * Math.sin( Math.PI / 4 );
 
-  var HYDROGEN_VIBRATION_DISTANCE = 30;
-  var HYDROGEN_VIBRATION_ANGLE = Math.PI / 4;
-  var HYDROGEN_VIBRATION_DISTANCE_X = HYDROGEN_VIBRATION_DISTANCE * Math.cos( HYDROGEN_VIBRATION_ANGLE );
-  var HYDROGEN_VIBRATION_DISTANCE_Y = HYDROGEN_VIBRATION_DISTANCE * Math.sin( HYDROGEN_VIBRATION_ANGLE );
+  const HYDROGEN_VIBRATION_DISTANCE = 30;
+  const HYDROGEN_VIBRATION_ANGLE = Math.PI / 4;
+  const HYDROGEN_VIBRATION_DISTANCE_X = HYDROGEN_VIBRATION_DISTANCE * Math.cos( HYDROGEN_VIBRATION_ANGLE );
+  const HYDROGEN_VIBRATION_DISTANCE_Y = HYDROGEN_VIBRATION_DISTANCE * Math.sin( HYDROGEN_VIBRATION_ANGLE );
 
   /**
    * Constructor for a Methane molecule.
@@ -102,7 +102,7 @@ define( require => {
       // Molecule.prototype.setVibration.call( this, vibrationRadians );
 
       this.currentVibrationRadians = vibrationRadians;
-      var multFactor = Math.sin( vibrationRadians );
+      const multFactor = Math.sin( vibrationRadians );
 
       if ( vibrationRadians !== 0 ) {
         this.addInitialAtomCogOffset( this.hydrogenAtom1, new Vector2( -ROTATED_INITIAL_CARBON_HYDROGEN_DISTANCE + multFactor * HYDROGEN_VIBRATION_DISTANCE_X,
@@ -115,10 +115,10 @@ define( require => {
           -ROTATED_INITIAL_CARBON_HYDROGEN_DISTANCE + multFactor * HYDROGEN_VIBRATION_DISTANCE_Y ) );
 
         // Position the carbon atom so that the center of mass of the molecule remains the same.
-        var carbonXPos = -( this.hydrogenAtom1.mass / this.carbonAtom.mass ) *
+        const carbonXPos = -( this.hydrogenAtom1.mass / this.carbonAtom.mass ) *
                          ( this.getInitialAtomCogOffset( this.hydrogenAtom1 ).x + this.getInitialAtomCogOffset( this.hydrogenAtom2 ).x +
                            this.getInitialAtomCogOffset( this.hydrogenAtom3 ).x + this.getInitialAtomCogOffset( this.hydrogenAtom4 ).x );
-        var carbonYPos = -( this.hydrogenAtom1.mass / this.carbonAtom.mass ) *
+        const carbonYPos = -( this.hydrogenAtom1.mass / this.carbonAtom.mass ) *
                          ( this.getInitialAtomCogOffset( this.hydrogenAtom1 ).y + this.getInitialAtomCogOffset( this.hydrogenAtom2 ).y +
                            this.getInitialAtomCogOffset( this.hydrogenAtom3 ).y + this.getInitialAtomCogOffset( this.hydrogenAtom4 ).y );
         this.addInitialAtomCogOffset( this.carbonAtom, new Vector2( carbonXPos, carbonYPos ) );

js/photon-absorption/model/molecules/CO.js

@@ -22,8 +22,8 @@ define( require => {
   const WavelengthConstants = require( 'MOLECULES_AND_LIGHT/photon-absorption/model/WavelengthConstants' );
 
   // Model Data for the carbon monoxide molecule
-  var INITIAL_CARBON_OXYGEN_DISTANCE = 170; // In picometers.
-  var VIBRATION_MAGNITUDE = 20; // In picometers.
+  const INITIAL_CARBON_OXYGEN_DISTANCE = 170; // In picometers.
+  const VIBRATION_MAGNITUDE = 20; // In picometers.
 
   /**
    * Constructor for a carbon monoxide molecule.
@@ -67,7 +67,7 @@ define( require => {
     setVibration: function( vibrationRadians ) {
 
       this.currentVibrationRadians = vibrationRadians;
-      var multFactor = Math.sin( vibrationRadians );
+      const multFactor = Math.sin( vibrationRadians );
       this.getVibrationAtomOffset( this.carbonAtom ).setXY( VIBRATION_MAGNITUDE * multFactor, 0 );
       this.getVibrationAtomOffset( this.oxygenAtom ).setXY( -VIBRATION_MAGNITUDE * multFactor, 0 );
       this.updateAtomPositions();