Boilerplate for our own ts transformer for our resource DTOs

Author: CarsonF

src/core/resources/plugin/index.cts

@@ -0,0 +1,25 @@
+import type * as ts from 'typescript';
+import {
+  ResourceReadonlyVisitor,
+  ResourceVisitor,
+  // @ts-expect-error the .cts extension is ok and needed for this one spot.
+  // This allows Nest CLI to CJS load it via ts-node
+} from './resources.visitor.cts';
+
+const visitor = new ResourceVisitor();
+
+// For ts-patch
+// eslint-disable-next-line import/no-default-export
+export default function (program: ts.Program) {
+  return before(undefined, program);
+}
+
+// For Nest CLI
+export { ResourceReadonlyVisitor as ReadonlyVisitor };
+export const before = (_: unknown, program: ts.Program) => {
+  return (ctx: ts.TransformationContext) => {
+    return (sf: ts.SourceFile) => {
+      return visitor.visit(sf, ctx, program);
+    };
+  };
+};

src/core/resources/plugin/resources.visitor.cts

@@ -0,0 +1,38 @@
+import type { ReadonlyVisitor } from '@nestjs/cli/lib/compiler/interfaces/readonly-visitor.interface';
+import * as ts from 'typescript';
+
+export class ResourceVisitor {
+  constructor(readonly readonly = false) {}
+
+  visit(sf: ts.SourceFile, ctx: ts.TransformationContext, program: ts.Program) {
+    const visitNode = (node: ts.Node): ts.Node => {
+      // TODO logic
+
+      if (this.readonly) {
+        ts.forEachChild(node, visitNode);
+      } else {
+        return ts.visitEachChild(node, visitNode, ctx);
+      }
+      return node;
+    };
+    return ts.visitNode(sf, visitNode);
+  }
+}
+
+export class ResourceReadonlyVisitor implements ReadonlyVisitor {
+  readonly key = '@cord/resources';
+  private readonly visitor = new ResourceVisitor(true);
+
+  get typeImports() {
+    return {};
+  }
+
+  visit(program: ts.Program, sf: ts.SourceFile) {
+    const factoryHost = { factory: ts.factory } as any;
+    return this.visitor.visit(sf, factoryHost, program);
+  }
+
+  collect() {
+    return {};
+  }
+}

tsconfig.json

@@ -36,6 +36,7 @@
     // Transform plugins
     "plugins": [
       { "transform": "typescript-transform-paths" },
+      { "transform": "./src/core/resources/plugin/index.cts" },
       { "transform": "ts-transformer-keys/transformer" },
     ],