Build code introspection service (#7760)

Starting to use ts-morph to retrieve function parameters

packages/twenty-server/src/modules/code-introspection/code-introspection.service.ts

@@ -0,0 +1,92 @@
+import { Injectable } from '@nestjs/common';
+
+import {
+  ArrowFunction,
+  FunctionDeclaration,
+  ParameterDeclaration,
+  Project,
+  SyntaxKind,
+} from 'ts-morph';
+
+import {
+  CodeIntrospectionException,
+  CodeIntrospectionExceptionCode,
+} from 'src/modules/code-introspection/code-introspection.exception';
+
+type FunctionParameter = {
+  name: string;
+  type: string;
+};
+
+@Injectable()
+export class CodeIntrospectionService {
+  private project: Project;
+
+  constructor() {
+    this.project = new Project();
+  }
+
+  public analyze(
+    fileContent: string,
+    fileName = 'temp.ts',
+  ): FunctionParameter[] {
+    const sourceFile = this.project.createSourceFile(fileName, fileContent, {
+      overwrite: true,
+    });
+
+    const functionDeclarations = sourceFile.getFunctions();
+
+    if (functionDeclarations.length > 0) {
+      return this.analyzeFunctions(functionDeclarations);
+    }
+
+    const arrowFunctions = sourceFile.getDescendantsOfKind(
+      SyntaxKind.ArrowFunction,
+    );
+
+    if (arrowFunctions.length > 0) {
+      return this.analyzeArrowFunctions(arrowFunctions);
+    }
+
+    return [];
+  }
+
+  private analyzeFunctions(
+    functionDeclarations: FunctionDeclaration[],
+  ): FunctionParameter[] {
+    if (functionDeclarations.length > 1) {
+      throw new CodeIntrospectionException(
+        'Only one function is allowed',
+        CodeIntrospectionExceptionCode.ONLY_ONE_FUNCTION_ALLOWED,
+      );
+    }
+
+    const functionDeclaration = functionDeclarations[0];
+
+    return functionDeclaration.getParameters().map(this.buildFunctionParameter);
+  }
+
+  private analyzeArrowFunctions(
+    arrowFunctions: ArrowFunction[],
+  ): FunctionParameter[] {
+    if (arrowFunctions.length > 1) {
+      throw new CodeIntrospectionException(
+        'Only one arrow function is allowed',
+        CodeIntrospectionExceptionCode.ONLY_ONE_FUNCTION_ALLOWED,
+      );
+    }
+
+    const arrowFunction = arrowFunctions[0];
+
+    return arrowFunction.getParameters().map(this.buildFunctionParameter);
+  }
+
+  private buildFunctionParameter(
+    parameter: ParameterDeclaration,
+  ): FunctionParameter {
+    return {
+      name: parameter.getName(),
+      type: parameter.getType().getText(),
+    };
+  }
+}