Prefix task function name

README.md

@@ -164,6 +164,10 @@ Result:
  end sub
 ```
 
+### Tasks (`m.top.functionName`)
+BrightScript Task objects have a special `m.top.functionName` property that specifies which function should be run during the task. ropm will find all instances of `m.top.functionName = "<anything>"` and add the prefix to the beginning of the string.
+
+The syntax must be exactly `m.top.functionName = ` followed by a string (i.e. `m.top.functionName = "taskCallback"`). ropm will skip the statement if anything other than a string is found to the right-hand-side of the equals sign. If you dynamically generate the value for `m.top.functionName`, or assign it in some other fashion, consider using the [ROPM_PREFIX](#ropm_prefix-source-literal) source literal instead.
 
 ### Never-prefixed functions
 Due to their special handling within the Roku architecture, the following functions  will never be prefixed:

src/prefixer/File.ts

@@ -62,7 +62,7 @@ export class File {
     }
 
     /**
-     * The full pkg path to the file (minus the `pkg:/` protocol since we never actually need that part
+     * The full pkg path to the file (minus the `pkg:/` protocol since we never actually need that part)
      */
     public pkgPath: string;
 
@@ -99,6 +99,15 @@ export class File {
         offset: number;
     }>;
 
+    /**
+     * Every instance of `m.top.functionName = "<anything>".
+     * Used only if this file is referenced by a Task
+     */
+    public taskFunctionNameAssignments = [] as Array<{
+        name: string;
+        offset: number;
+    }>;
+
     /**
      * A list of locations in this file that DECLARE a component (i.e. <component name="<component_name"
      */
@@ -209,6 +218,7 @@ export class File {
             this.findCreateObjectComponentReferences();
             this.findCreateChildComponentReferences();
             this.findObserveFieldFunctionCalls();
+            this.findTaskFunctionNameAssignments();
             this.walkAst();
         } else if (this.isXmlFile) {
             this.findFilePathStrings();
@@ -557,6 +567,21 @@ export class File {
             }
         }
     }
+
+    /**
+     * Look for every statement that looks exactly like the default task functionName assignment.
+     */
+    private findTaskFunctionNameAssignments() {
+        //look for any string containing `m.top.functionName = "<anything>"`
+        const regexp = /(m\s*\.\s*top\s*\.\s*functionName\s*=\s*")(.*?)"/gi;
+        let match: RegExpExecArray | null;
+        while (match = regexp.exec(this.bscFile.fileContents)) {
+            this.taskFunctionNameAssignments.push({
+                offset: match.index + match[1].length,
+                name: match[2]
+            });
+        }
+    }
 }
 
 export interface Edit {

src/prefixer/ModuleManager.spec.ts

@@ -1315,6 +1315,107 @@ describe('ModuleManager', () => {
             });
         });
 
+        it('prefixes m.top.functionName for files NOT imported by a Task', async () => {
+            await testProcess({
+                'logger:source/lib.brs': [
+                    trim`
+                        sub a()
+                            m.top.functionName = "doSomething"
+                        end sub
+                    `,
+                    trim`
+                        sub logger_a()
+                            m.top.functionName = "logger_doSomething"
+                        end sub
+                    `]
+            });
+        });
+
+        it('prefixes direct task reference from component in same module', async () => {
+            await testProcess({
+                'logger:components/SimpleTask.brs': [
+                    trim`
+                        sub init()
+                            m.top.functionName = "doSomething"
+                        end sub
+                    `, trim`
+                        sub init()
+                            m.top.functionName = "logger_doSomething"
+                        end sub
+                    `
+                ],
+                //directly extends task
+                'logger:components/SimpleTask.xml': [
+                    trim`
+                        <?xml version="1.0" encoding="utf-8" ?>
+                        <component name="SimpleTask" extends="Task">
+                            <script uri="SimpleTask.brs" />
+                        </component>
+                    `
+                ]
+            });
+        });
+
+        it('prefixes indirect task reference from component in same module', async () => {
+            await testProcess({
+                'logger:components/HardTask.brs': [
+                    trim`
+                        sub init()
+                            m.top.functionName = "doSomething"
+                        end sub
+                    `, trim`
+                        sub init()
+                            m.top.functionName = "logger_doSomething"
+                        end sub
+                    `
+                ],
+                'logger:components/SimpleTask.xml': [
+                    trim`
+                        <?xml version="1.0" encoding="utf-8" ?>
+                        <component name="SimpleTask" extends="Task">
+                        </component>
+                    `
+                ], 'logger:components/HardTask.xml': [
+                    trim`
+                        <?xml version="1.0" encoding="utf-8" ?>
+                        <component name="HardTask" extends="SimpleTask">
+                            <script uri="HardTask.brs" />
+                        </component>
+                    `
+                ]
+            });
+        });
+
+        it('prefixes indirect task reference from component in different module', async () => {
+            await testProcess({
+                'logger:components/HardTask.brs': [
+                    trim`
+                        sub init()
+                            m.top.functionName = "doSomething"
+                        end sub
+                    `, trim`
+                        sub init()
+                            m.top.functionName = "logger_doSomething"
+                        end sub
+                    `
+                ],
+                'tasker:components/SimpleTask.xml': [
+                    trim`
+                        <?xml version="1.0" encoding="utf-8" ?>
+                        <component name="SimpleTask" extends="Task">
+                        </component>
+                    `
+                ], 'logger:components/HardTask.xml': [
+                    trim`
+                        <?xml version="1.0" encoding="utf-8" ?>
+                        <component name="HardTask" extends="tasker_SimpleTask">
+                            <script uri="HardTask.brs" />
+                        </component>
+                    `
+                ]
+            });
+        });
+
         it('prefixes namespaces and not their child functions or classes', async () => {
             await testProcess({
                 'logger:source/lib.d.bs': [

src/prefixer/RopmModule.ts

@@ -51,6 +51,8 @@ export class RopmModule {
         '!**/roku_modules/**/*'
     ];
 
+    public files = [] as File[];
+
     /**
      * The name of this module. Users can rename modules on install-time, so this is the folder we must use
      */
@@ -235,6 +237,7 @@ export class RopmModule {
             file.discover(this.program);
         }
 
+
         //create the edits for every file
         this.createEdits(noprefixRopmAliases);
 
@@ -318,6 +321,11 @@ export class RopmModule {
             //only apply prefixes if configured to do so
             if (applyOwnPrefix) {
 
+                // replace `m.top.functionName = "<anything>"` assignments to support Tasks
+                for (const ref of file.taskFunctionNameAssignments) {
+                    file.addEdit(ref.offset, ref.offset, prefix);
+                }
+
                 //create an edit for each this-module-owned function
                 for (const func of file.functionDefinitions) {
                     const lowerName = func.name.toLowerCase();
@@ -541,7 +549,4 @@ export class RopmModule {
         }
         return Object.keys(result);
     }
-
-
-    public files = [] as File[];
 }