From 6cf505ac71d96ebb5e8c2f5f689cffdbe22d06c7 Mon Sep 17 00:00:00 2001
From: David Wilson <daviwil@microsoft.com>
Date: Thu, 25 Mar 2021 11:23:03 -0700
Subject: [PATCH] Add `@minValue` and `@maxValue` decorators for numeric types

---
 packages/adl/lib/decorators.ts               | 49 ++++++++++++++++++++
 packages/adl/test/decorators/range-limits.ts | 29 ++++++++++++
 2 files changed, 78 insertions(+)
 create mode 100644 packages/adl/test/decorators/range-limits.ts

diff --git a/packages/adl/lib/decorators.ts b/packages/adl/lib/decorators.ts
index 03310afb7..7b654f990 100644
--- a/packages/adl/lib/decorators.ts
+++ b/packages/adl/lib/decorators.ts
@@ -112,6 +112,55 @@ export function getMaxLength(target: Type): number | undefined {
   return maxLengthValues.get(target);
 }
 
+// -- @minValue decorator ---------------------
+
+const minValues = new Map<Type, number>();
+
+export function isNumericType(target: Type): boolean {
+  const intrinsicType = getIntrinsicType(target);
+  return (
+    intrinsicType !== undefined && ["int32", "int64", "float32", "float64"].includes(intrinsicType)
+  );
+}
+
+export function minValue(program: Program, target: Type, minValue: number) {
+  if (target.kind === "Model" || target.kind === "ModelProperty") {
+    // Is it ultimately a numeric type?
+    if (isNumericType(target)) {
+      minValues.set(target, minValue);
+    } else {
+      throw new Error("Cannot apply @minValue to a non-numeric type");
+    }
+  } else {
+    throw new Error("Cannot apply @minValue to anything that isn't a Model or ModelProperty");
+  }
+}
+
+export function getMinValue(target: Type): number | undefined {
+  return minValues.get(target);
+}
+
+// -- @maxValue decorator ---------------------
+
+const maxValues = new Map<Type, number>();
+
+export function maxValue(program: Program, target: Type, maxValue: number) {
+  if (target.kind === "Model" || target.kind === "ModelProperty") {
+    // Is it ultimately a numeric type?
+    if (isNumericType(target)) {
+      maxValues.set(target, maxValue);
+    } else {
+      throw new Error("Cannot apply @maxValue to a non-numeric type");
+    }
+  } else {
+    throw new Error("Cannot apply @maxValue to anything that isn't a Model or ModelProperty");
+  }
+}
+
+export function getMaxValue(target: Type): number | undefined {
+  return maxValues.get(target);
+}
+
 // -- @secret decorator ---------------------
 
 const secretTypes = new Map<Type, boolean>();
diff --git a/packages/adl/test/decorators/range-limits.ts b/packages/adl/test/decorators/range-limits.ts
new file mode 100644
index 000000000..faa30ac0c
--- /dev/null
+++ b/packages/adl/test/decorators/range-limits.ts
@@ -0,0 +1,29 @@
+import { strictEqual, ok } from "assert";
+import { ModelType, Type } from "../../compiler/types.js";
+import { createTestHost, TestHost } from "../test-host.js";
+import { getMinValue, getMaxValue } from "../../lib/decorators.js";
+
+describe("range limiting decorators", () => {
+  let testHost: TestHost;
+
+  beforeEach(async () => {
+    testHost = await createTestHost();
+  });
+
+  it("applies @minimum and @maximum decorators", async () => {
+    testHost.addAdlFile(
+      "a.adl",
+      `
+      @test model A { @minValue 15 foo: int32; @maxValue 55 boo: float32; }
+      @test model B { @maxValue 20 bar: int64; @minValue 23 car: float64; }
+      `
+    );
+
+    const { A, B } = (await testHost.compile("./")) as { A: ModelType; B: ModelType };
+
+    strictEqual(getMinValue(A.properties.get("foo")!), 15);
+    strictEqual(getMaxValue(A.properties.get("boo")!), 55);
+    strictEqual(getMaxValue(B.properties.get("bar")!), 20);
+    strictEqual(getMinValue(B.properties.get("car")!), 23);
+  });
+});