start extracting ts-generation code (#11)

* start extracting ts-generation code

* add csb

Author: phryneas

.codesandbox/ci.json

@@ -0,0 +1,3 @@
+{
+  "sandboxes": ["new"]
+}

src/codegen.ts

@@ -0,0 +1,129 @@
+import * as ts from 'typescript';
+const { factory } = ts;
+
+const defaultEndpointBuilder = factory.createIdentifier('build');
+
+export type ObjectPropertyDefinitions = Record<string, ts.Expression>;
+export function generateObjectProperties(obj: ObjectPropertyDefinitions) {
+  return Object.entries(obj).map(([k, v]) => factory.createPropertyAssignment(factory.createIdentifier(k), v));
+}
+
+export function generateStringLiteralArray(arr: string[]) {
+  return factory.createArrayLiteralExpression(
+    arr.map((elem) => factory.createStringLiteral(elem)),
+    false
+  );
+}
+
+export function generateImportNode(pkg: string, namedImports: Record<string, string>, defaultImportName?: string) {
+  return factory.createImportDeclaration(
+    undefined,
+    undefined,
+    factory.createImportClause(
+      false,
+      defaultImportName !== undefined ? factory.createIdentifier(defaultImportName) : undefined,
+      factory.createNamedImports(
+        Object.entries(namedImports).map(([propertyName, name]) =>
+          factory.createImportSpecifier(
+            name === propertyName ? undefined : factory.createIdentifier(propertyName),
+            factory.createIdentifier(name)
+          )
+        )
+      )
+    ),
+    factory.createStringLiteral(pkg)
+  );
+}
+
+export function generateCreateApiCall({
+  exportName,
+  reducerPath,
+  createApiFn,
+  baseQuery,
+  entityTypes,
+  endpointBuilder = defaultEndpointBuilder,
+  endpointDefinitions,
+}: {
+  exportName: string;
+  reducerPath?: string;
+  createApiFn: ts.Expression;
+  baseQuery: ts.Expression;
+  entityTypes: ts.Expression;
+  endpointBuilder?: ts.Identifier;
+  endpointDefinitions: ts.ObjectLiteralExpression;
+}) {
+  return factory.createVariableStatement(
+    [factory.createModifier(ts.SyntaxKind.ExportKeyword)],
+    factory.createVariableDeclarationList(
+      [
+        factory.createVariableDeclaration(
+          factory.createIdentifier(exportName),
+          undefined,
+          undefined,
+          factory.createCallExpression(createApiFn, undefined, [
+            factory.createObjectLiteralExpression(
+              generateObjectProperties({
+                ...(!reducerPath ? {} : { reducerPath: factory.createStringLiteral(reducerPath) }),
+                baseQuery,
+                entityTypes,
+                endpoints: factory.createArrowFunction(
+                  undefined,
+                  undefined,
+                  [
+                    factory.createParameterDeclaration(
+                      undefined,
+                      undefined,
+                      undefined,
+                      endpointBuilder,
+                      undefined,
+                      undefined,
+                      undefined
+                    ),
+                  ],
+                  undefined,
+                  factory.createToken(ts.SyntaxKind.EqualsGreaterThanToken),
+                  factory.createParenthesizedExpression(endpointDefinitions)
+                ),
+              }),
+              true
+            ),
+          ])
+        ),
+      ],
+      ts.NodeFlags.Const
+    )
+  );
+}
+
+export function generateEndpointDefinition({
+  operationName,
+  type,
+  Response,
+  QueryArg,
+  queryFn,
+  endpointBuilder = defaultEndpointBuilder,
+  extraEndpointsProps,
+}: {
+  operationName: string;
+  type: 'query' | 'mutation';
+  Response: ts.TypeReferenceNode;
+  QueryArg: ts.TypeReferenceNode;
+  queryFn: ts.Expression;
+  endpointBuilder?: ts.Identifier;
+  extraEndpointsProps: ObjectPropertyDefinitions;
+}) {
+  return factory.createPropertyAssignment(
+    factory.createIdentifier(operationName),
+
+    factory.createCallExpression(
+      factory.createPropertyAccessExpression(endpointBuilder, factory.createIdentifier(type)),
+      [Response, QueryArg],
+      [
+        factory.createObjectLiteralExpression(
+          generateObjectProperties({ query: queryFn, ...extraEndpointsProps }),
+          true
+        ),
+      ]
+    )
+  );
+}