Let users use or discard explicit types (#744)

* Add a useExplicitTypes configuration option

* Prevent writing the 'as type' when useExplicitType is false

* Add documentation for the useExplicitTypes config

* Rename option to removeParameterTypes

Co-authored-by: Bronley Plumb <bronley@gmail.com>

README.md

@@ -250,6 +250,12 @@ Type: `boolean`
 
 Prevent the staging folder from being deleted after creating the package. Defaults to `false`, meaning that the folder is deleted every time.
 
+#### `removeParameterTypes`
+
+Type: `boolean`
+
+If true, removes the explicit type to function's parameters and return (i.e. the `as type` syntax); otherwise keep this information.
+
 #### `files`
 
 Type:

bsconfig.schema.json

@@ -149,6 +149,11 @@
             "type": "boolean",
             "default": false
         },
+        "removeParameterTypes": {
+            "description": "Removes the explicit type to function's parameters and return (i.e. the `as type` syntax) ",
+            "type": "boolean",
+            "default": false
+        },
         "diagnosticFilters": {
             "description": "A collection of filters used to hide diagnostics for certain files",
             "type": "array",

src/BsConfig.ts

@@ -117,6 +117,12 @@ export interface BsConfig {
      */
     emitDefinitions?: boolean;
 
+    /**
+     * If true, removes the explicit type to function's parameters and return (i.e. the `as type` syntax); otherwise keep this information.
+     * @default false
+     */
+    removeParameterTypes?: boolean;
+
     /**
      * A list of filters used to exclude diagnostics from the output
      */

src/files/BrsFile.spec.ts

@@ -2332,6 +2332,30 @@ describe('BrsFile', () => {
             `);
         });
 
+        it('discard parameter types when removeParameterTypes is true', () => {
+            program.options.removeParameterTypes = true;
+            testTranspile(`
+                sub one(a as integer, b = "" as string, c = invalid as dynamic)
+                end sub
+            `, `
+                sub one(a, b = "", c = invalid)
+                end sub
+            `);
+        });
+
+        it('discard return type when removeParameterTypes is true', () => {
+            program.options.removeParameterTypes = true;
+            testTranspile(`
+                function one() as string
+                    return ""
+                end function
+            `, `
+                function one()
+                    return ""
+                end function
+            `);
+        });
+
         it('transpiles local var assignment operators', () => {
             testTranspile(`
                 sub main()

src/parser/Expression.ts

@@ -232,7 +232,7 @@ export class FunctionExpression extends Expression implements TypedefProvider {
             state.transpileToken(this.rightParen)
         );
         //as [Type]
-        if (this.asToken) {
+        if (this.asToken && !state.options.removeParameterTypes) {
             results.push(
                 ' ',
                 //as
@@ -317,7 +317,7 @@ export class FunctionParameterExpression extends Expression {
             result.push(this.defaultValue.transpile(state));
         }
         //type declaration
-        if (this.asToken) {
+        if (this.asToken && !state.options.removeParameterTypes) {
             result.push(' ');
             result.push(state.transpileToken(this.asToken));
             result.push(' ');

src/util.ts

@@ -343,6 +343,7 @@ export class Util {
         config.sourceRoot = config.sourceRoot ? standardizePath(config.sourceRoot) : undefined;
         config.allowBrighterScriptInBrightScript = config.allowBrighterScriptInBrightScript === true ? true : false;
         config.emitDefinitions = config.emitDefinitions === true ? true : false;
+        config.removeParameterTypes = config.removeParameterTypes === true ? true : false;
         if (typeof config.logLevel === 'string') {
             config.logLevel = LogLevel[(config.logLevel as string).toLowerCase()];
         }