some refinements in the plugin

README.md

@@ -16,7 +16,7 @@ Have a look at the section under `/src/experiment` and `/src/plugins`:
 - `src/plugins/typeInferPlugin.ts` is the actual plugin
 - in `tsconfig.json` we configure TypeScript to run the plugin
 - `src/experiment/arithmeticInfer.ts` with an example where we define `__infer__`
-- `build/experiment/arithmeticInfer.ts` where the `__infer__` string literal is replace with the actual types
+- after running TypeScript: look at `build/experiment/arithmeticInfer.ts` where the `__infer__` string literal is replaced with the actual types
 
 ### The idea
 

src/core/typed.ts

@@ -1,14 +1,9 @@
-export function infer<T>(arg: T) : T {
-  console.error('infer should be replaced with runtime type information by a magic TypeScript plugin')
-  return arg
-}
-
 export function typed<T>(name: string, types: string, arg: T) : T {
   // TODO: implement typed-function for real
   if (types === '__infer__') {
     console.error('__infer__ should be replaced with runtime type information by the TypeScript plugin')
   }
 
-  console.log(`Creating typed-function "${name}" with types ${types}`)
+  console.log(`TYPED-FUNCTION: Creating function "${name}" with types ${types}`)
   return arg
 }

src/experiment/arithmeticInfer.ts

@@ -1,4 +1,4 @@
-import { typed } from '../generic/infer'
+import { typed } from '../core/typed.js'
 
 export const square = typed('square', '__infer__', <T>(dep: {
   multiply: (a: T, b: T) => T,

src/plugins/typeInferPlugin.ts

@@ -6,32 +6,30 @@ const transformer: ts.TransformerFactory<ts.SourceFile> = context => {
   const checker = program.getTypeChecker()
 
   return sourceFile => {
-    // For the experiment we only want to influence a single file
-    if (!sourceFile.fileName.endsWith('arithmeticInfer.ts')) {
-      return sourceFile
-    }
-
     const visitor = (node: ts.Node): ts.Node => {
       // @ts-ignore
       if (ts.isStringLiteral(node) && node.text === '__infer__') {
-        console.log('FOUND AN OCCURRENCE OF __infer__')
+        console.log('PLUGIN: FOUND AN OCCURRENCE OF __infer__')
 
+        // we're looking for a function call like typed('name', '__infer__', deps => ...)
         const parentNode = node.parent
+        if (ts.isCallExpression(parentNode) && ts.isIdentifier(parentNode.expression) && parentNode.expression.escapedText === 'typed') {
           // console.log('PARENT')
           // console.log(parentNode)
 
-        // TODO: validate that the parent is indeed a mathjs typed function with deps
+          // TODO: validate that argNode is an ArrowFunction
-
           // @ts-ignore
           const argNode = parentNode.arguments[2]
+          // @ts-ignore
           const returnType = argNode.type.getText(sourceFile)
-        console.log('RETURN TYPE')
+          console.log('PLUGIN: RETURN TYPE')
           console.log(returnType)
           // (a: number) => number
 
+          // @ts-ignore
           const paramNode = argNode.parameters[0]
           const paramTypeSrc = paramNode.type.getText(sourceFile)
-        console.log('PARAM TYPE SRC', paramTypeSrc)
+          console.log('PLUGIN: PARAM TYPE SRC', paramTypeSrc)
           // {
           //   multiply: (a: number, b: number) => number,
           //   unaryMinus: (x: number) => number, // just for the experiment
@@ -39,13 +37,14 @@ const transformer: ts.TransformerFactory<ts.SourceFile> = context => {
 
           const type = checker.getTypeAtLocation(paramNode)
           const paramType = checker.typeToString(type, paramNode, ts.TypeFormatFlags.InTypeAlias)
-        console.log('PARAM TYPE STRING', paramType)
+          console.log('PLUGIN: PARAM TYPE STRING', paramType)
           // { multiply: (a: number, b: number) => number; unaryMinus: (x: number) => number; }
 
           const depsAndReturnType = `{ deps: ${paramType}; return: ${returnType} }`
 
           return ts.factory.createStringLiteral(depsAndReturnType)
         }
+      }
 
       return ts.visitEachChild(node, visitor, context)
     }