Shorthand can reference other shorthands

lib/utils.js

@@ -116,7 +116,24 @@ const applyType = (type, extendingTypeShorthands = {}) => {
     ...extendingTypeShorthands
   };
   const options = typeof type === "string" ? { type } : type;
-  const ext = typeShorthands[options.type] || { type: options.type };
+  let ext = null;
+  const types = [options.type];
+  while (typeShorthands[types[types.length - 1]]) {
+    if (ext) {
+      delete ext.type;
+    }
+    ext = { ...typeShorthands[types[types.length - 1]], ...ext };
+    if (types.includes(ext.type)) {
+      throw new Error(
+        `Shorthands contain cyclic dependency: ${types.join(", ")}, ${ext.type}`
+      );
+    } else {
+      types.push(ext.type);
+    }
+  }
+  if (!ext) {
+    ext = { type: options.type };
+  }
   return {
     ...ext,
     ...options,

test/utils-test.js

@@ -1,5 +1,5 @@
 const { expect } = require("chai");
-const { escapeValue, PgLiteral } = require("../lib/utils");
+const { escapeValue, PgLiteral, applyType } = require("../lib/utils");
 
 describe("lib/utils", () => {
   describe(".escapeValue", () => {
@@ -49,4 +49,44 @@ describe("lib/utils", () => {
       expect(escapeValue(value)).to.equal("");
     });
   });
+
+  describe(".applyType", () => {
+    it("convert string", () => {
+      const type = "type";
+
+      expect(applyType(type)).to.eql({ type });
+    });
+
+    it("apply id shorthand", () => {
+      expect(applyType("id")).to.eql({ type: "serial", primaryKey: true });
+    });
+
+    it("apply shorthand", () => {
+      const shorthandName = "type";
+      const shorthandDefinition = { type: "integer", defaultValue: 1 };
+      expect(
+        applyType(shorthandName, { [shorthandName]: shorthandDefinition })
+      ).to.eql(shorthandDefinition);
+    });
+
+    it("apply recursive shorthand", () => {
+      const shorthands = {
+        ref: { type: `integer`, onDelete: `cascade` },
+        user: { type: `ref`, references: `users` }
+      };
+      expect(applyType("user", shorthands)).to.eql({
+        type: `integer`,
+        onDelete: `cascade`,
+        references: `users`
+      });
+    });
+
+    it("detect cycle in recursive shorthand", () => {
+      const shorthands = {
+        ref: { type: `user`, onDelete: `cascade` },
+        user: { type: `ref`, references: `users` }
+      };
+      expect(() => applyType("user", shorthands)).to.throw();
+    });
+  });
 });