Add use statement for declarations

Author: canmingir

src/routes/terminal.js

@@ -7,23 +7,27 @@ const metrics = require("./metrics");
 const runtime = require("../runtime");
 
 const terminal = express();
-terminal.use(express.json());
-terminal.use(express.text({ type: "application/javascript" }));
 terminal.use(cors());
 
+terminal.post(
+  "/",
+  (req, res, next) =>
+    req.is("application/javascript") ? next() : res.status(415).end(),
+  express.text({ type: "application/javascript" }),
+  (req, res) => {
+    const details = runtime.process(req.body, { details: true });
+    res.send(details);
+  }
+);
+
+terminal.use(express.json(), (err, req, res, next) =>
+  err ? res.status(422).end() : next()
+);
 terminal.use(graph);
 terminal.use(openapi);
 terminal.use(logs);
 terminal.use(metrics);
 
-terminal.post("/", (req, res) => {
-  const mode = req.headers["x-nuc-mode"];
-  const declarative = mode?.toLowerCase() === "declarative";
-  const details = runtime.process(req.body, { declarative, details: true });
-
-  res.send(details);
-});
-
 // eslint-disable-next-line no-unused-vars
 terminal.use((err, req, res, next) => {
   if (typeof err === "string") {

src/runtime.js

@@ -20,13 +20,17 @@ try {
 module.exports.process = function (string, options = {}) {
   const { options: configOptions } = config();
   options = { ...defaultOptions, ...configOptions, ...options };
-  const { declarative, details } = options;
 
   const before = Date.now();
   let result;
 
   try {
-    const statements = Statement.compile(string, options);
+    const statements = Statement.compile(string);
+
+    if (!statements.length) {
+      return;
+    }
+
     transaction.start();
     result = stack.process(statements, null, options);
     transaction.end();
@@ -42,7 +46,7 @@ module.exports.process = function (string, options = {}) {
   datastore.write({
     s: string,
     $: result.$nuc?.length ? result.$nuc : undefined,
-    c: declarative ? true : undefined,
+    c: options.declarative ? true : undefined,
     t: time,
     r: result.value,
     d: date,
@@ -56,11 +60,11 @@ module.exports.process = function (string, options = {}) {
 
   Event.clear();
 
-  if (details) {
+  if (options.details) {
     return {
       result: result.value,
       $nuc: result.$nuc,
-      declarative,
+      declarative: options.declarative,
       date,
       time,
       error: !!result.error,

src/stack.js

@@ -13,7 +13,6 @@ const RETURN = require("./nuc/RETURN");
 
 function process(statements, prior, options = {}) {
   const root = new Scope(prior);
-  const { declarative } = options;
 
   let instructions = statements.map(
     (statement) =>
@@ -61,6 +60,14 @@ function process(statements, prior, options = {}) {
           value = state.expression(scope, evaluation);
         }
 
+        if (value === "use declarative") {
+          options.declarative = true;
+        }
+
+        if (value === "use imperative") {
+          options.declarative = false;
+        }
+
         if (instruction.scope === root && !instruction.derivative) {
           result.value = value;
         }
@@ -217,7 +224,7 @@ function process(statements, prior, options = {}) {
 
             let list = statement.graph(instruction.scope);
 
-            if (declarative) {
+            if (options.declarative) {
               if (list) {
                 list.forEach((target) => {
                   if (target.previous[statement.key] !== undefined) {