add readonly to public static fields, phetsims/tandem#278

js/common/model/ConcentrationModel.ts

@@ -39,24 +39,24 @@ assert && assert( CLOUD_VISIBLE_REFLECTIVITY <= 1, `invalid reflectivity value f
 // An enumeration for how concentration can be controlled, either by direct value or by selecting a value for Earth's
 // concentration at a particular date.
 class ConcentrationControlMode extends EnumerationValue {
-  public static BY_VALUE = new ConcentrationControlMode();
-  public static BY_DATE = new ConcentrationControlMode();
+  public static readonly BY_VALUE = new ConcentrationControlMode();
+  public static readonly BY_DATE = new ConcentrationControlMode();
 
   // Gets a list of keys, values and mapping between them.  For use in EnumerationProperty and PhET-iO
-  public static enumeration = new Enumeration( ConcentrationControlMode, {
+  public static readonly enumeration = new Enumeration( ConcentrationControlMode, {
     phetioDocumentation: 'Describes the mode by which concentration is controlled, either by date or by value.'
   } );
 }
 
 // dates with recorded values of greenhouse concentration
 class ConcentrationDate extends EnumerationValue {
-  public static ICE_AGE = new ConcentrationDate();
-  public static SEVENTEEN_FIFTY = new ConcentrationDate();
-  public static NINETEEN_FIFTY = new ConcentrationDate();
-  public static TWENTY_TWENTY = new ConcentrationDate();
+  public static readonly ICE_AGE = new ConcentrationDate();
+  public static readonly SEVENTEEN_FIFTY = new ConcentrationDate();
+  public static readonly NINETEEN_FIFTY = new ConcentrationDate();
+  public static readonly TWENTY_TWENTY = new ConcentrationDate();
 
   // Gets a list of keys, values and mapping between them.  For use in EnumerationProperty and PhET-iO
-  public static enumeration = new Enumeration( ConcentrationDate, {
+  public static readonly enumeration = new Enumeration( ConcentrationDate, {
     phetioDocumentation: 'Various time periods or years that can be used to define what greenhouse concentration value is ued.'
   } );
 }

js/common/model/EnergyAbsorbingEmittingLayer.ts

@@ -47,10 +47,10 @@ class Substance extends EnumerationValue {
     this.radiationDirections = radiationDirections;
   }
 
-  public static GLASS = new Substance( 2500, 840, [ EnergyDirection.UP, EnergyDirection.DOWN ] );
-  public static EARTH = new Substance( 1250, 1250, [ EnergyDirection.UP ] );
+  public static readonly GLASS = new Substance( 2500, 840, [ EnergyDirection.UP, EnergyDirection.DOWN ] );
+  public static readonly EARTH = new Substance( 1250, 1250, [ EnergyDirection.UP ] );
 
-  public static enumeration = new Enumeration( Substance );
+  public static readonly enumeration = new Enumeration( Substance );
 }
 
 // The size of the energy absorbing layers are all the same in the Greenhouse Effect sim and are not parameterized.

js/common/model/EnergyDirection.ts

@@ -15,32 +15,32 @@ const UP_VECTOR = new Vector2( 0, 1 );
 const DOWN_VECTOR = new Vector2( 0, -1 );
 
 class EnergyDirection extends EnumerationValue {
-  public static UP = new EnergyDirection();
-  public static DOWN = new EnergyDirection();
+  public static readonly UP = new EnergyDirection();
+  public static readonly DOWN = new EnergyDirection();
 
   /**
    * Get a vector corresponding to the provided enum value.
    */
-  public static toVector = ( enumValue: EnergyDirection ): Vector2 => {
+  public static toVector( enumValue: EnergyDirection ): Vector2 {
     if ( enumValue === EnergyDirection.UP ) {
       return UP_VECTOR;
     }
     else {
       assert && assert( enumValue === EnergyDirection.DOWN, 'illegal direction' );
       return DOWN_VECTOR;
     }
-  };
+  }
 
   /**
    * Get the opposite of the provided direction.
    */
-  public static getOpposite = ( enumValue: EnergyDirection ): EnergyDirection => {
+  public static getOpposite( enumValue: EnergyDirection ): EnergyDirection {
     return enumValue === EnergyDirection.UP ?
            EnergyDirection.DOWN :
            EnergyDirection.UP;
-  };
+  }
 
-  public static enumeration = new Enumeration( EnergyDirection );
+  public static readonly enumeration = new Enumeration( EnergyDirection );
 }
 
 greenhouseEffect.register( 'EnergyDirection', EnergyDirection );

js/common/model/Photon.ts

@@ -28,10 +28,10 @@ const SUPPORTED_WAVELENGTHS = [ IR_WAVELENGTH, VISIBLE_WAVELENGTH ];
 
 // types and enumerations
 class ShowState extends EnumerationValue {
-  public static ALWAYS = new ShowState();
-  public static ONLY_IN_MORE_PHOTONS_MODE = new ShowState();
+  public static readonly ALWAYS = new ShowState();
+  public static readonly ONLY_IN_MORE_PHOTONS_MODE = new ShowState();
 
-  public static enumeration = new Enumeration( ShowState );
+  public static readonly enumeration = new Enumeration( ShowState );
 }
 
 export type PhotonOptions = {

js/common/model/PhotonAbsorbingEmittingLayer.ts

@@ -21,13 +21,13 @@ import Photon from './Photon.js';
 
 // enum that enumerates the possible results when testing whether a photon crossed a layer
 class PhotonCrossingTestResult extends EnumerationValue {
-  public static FULLY_ABOVE = new PhotonCrossingTestResult();
-  public static FULLY_BELOW = new PhotonCrossingTestResult();
-  public static CROSSED_BUT_IGNORED = new PhotonCrossingTestResult();
-  public static CROSSED_AND_ABSORBED = new PhotonCrossingTestResult();
-  public static NONE = new PhotonCrossingTestResult();
+  public static readonly FULLY_ABOVE = new PhotonCrossingTestResult();
+  public static readonly FULLY_BELOW = new PhotonCrossingTestResult();
+  public static readonly CROSSED_BUT_IGNORED = new PhotonCrossingTestResult();
+  public static readonly CROSSED_AND_ABSORBED = new PhotonCrossingTestResult();
+  public static readonly NONE = new PhotonCrossingTestResult();
 
-  public static enumeration = new Enumeration( PhotonCrossingTestResult );
+  public static readonly enumeration = new Enumeration( PhotonCrossingTestResult );
 }
 
 type PhotonAbsorbingEmittingLayerOptions = {

js/common/model/TemperatureUnits.ts

@@ -9,12 +9,12 @@ import greenhouseEffect from '../../greenhouseEffect.js';
  */
 
 class TemperatureUnits extends EnumerationValue {
-  public static KELVIN = new TemperatureUnits();
-  public static CELSIUS = new TemperatureUnits();
-  public static FAHRENHEIT = new TemperatureUnits();
+  public static readonly KELVIN = new TemperatureUnits();
+  public static readonly CELSIUS = new TemperatureUnits();
+  public static readonly FAHRENHEIT = new TemperatureUnits();
 
   // Gets a list of keys, values and mapping between them.  For use in EnumerationProperty and PhET-iO
-  public static enumeration = new Enumeration( TemperatureUnits, {
+  public static readonly enumeration = new Enumeration( TemperatureUnits, {
     phetioDocumentation: 'Describes the type of the mammal.'
   } );
 }

js/common/view/EnergyLegend.ts

@@ -34,9 +34,9 @@ const PANEL_MARGIN = 8;
 
 // The legend can display photon or wave representation of energy, see energyRepresentation option
 class EnergyRepresentation extends EnumerationValue {
-  public static PHOTON = new EnergyRepresentation();
-  public static WAVE = new EnergyRepresentation();
-  public static enumeration = new Enumeration( EnergyRepresentation );
+  public static readonly PHOTON = new EnergyRepresentation();
+  public static readonly WAVE = new EnergyRepresentation();
+  public static readonly enumeration = new Enumeration( EnergyRepresentation );
 }
 
 type SelfOptions = {

js/common/view/ThermometerAndReadout.ts

@@ -41,10 +41,10 @@ const celsiusUnitsStringProperty = GreenhouseEffectStrings.temperature.units.cel
 const fahrenheitUnitsStringProperty = GreenhouseEffectStrings.temperature.units.fahrenheitStringProperty;
 
 class ReadoutType extends EnumerationValue {
-  public static SELECTABLE = new ReadoutType();
-  public static FIXED = new ReadoutType();
+  public static readonly SELECTABLE = new ReadoutType();
+  public static readonly FIXED = new ReadoutType();
 
-  public static enumeration = new Enumeration( ReadoutType );
+  public static readonly enumeration = new Enumeration( ReadoutType );
 }
 
 type SelfOptions = {