Add type definitions for assertion methods (#11883)

Co-authored-by: Nicolò Ribaudo <nicolo.ribaudo@gmail.com>

packages/babel-types/scripts/generators/flow.js

@@ -113,17 +113,25 @@ for (const type in t.NODE_FIELDS) {
   }
 }
 
-for (let i = 0; i < t.TYPES.length; i++) {
+for (const typeName of t.TYPES) {
-  let decl = `declare function is${t.TYPES[i]}(node: ?Object, opts?: ?Object): boolean`;
+  const isDeprecated = !!t.DEPRECATED_KEYS[typeName];
+  const realName = isDeprecated ? t.DEPRECATED_KEYS[typeName] : typeName;
 
-  if (t.NODE_FIELDS[t.TYPES[i]]) {
+  let decl = `declare function is${typeName}(node: ?Object, opts?: ?Object): boolean`;
-    decl += ` %checks (node instanceof ${NODE_PREFIX}${t.TYPES[i]})`;
+  if (t.NODE_FIELDS[realName]) {
+    decl += ` %checks (node instanceof ${NODE_PREFIX}${realName})`;
   }
-
   lines.push(decl);
+
+  lines.push(
+    `declare function assert${typeName}(node: ?Object, opts?: ?Object): void`
+  );
 }
 
 lines.push(
+  // assert/
+  `declare function assertNode(obj: any): void`,
+
   // builders/
   // eslint-disable-next-line max-len
   `declare function createTypeAnnotationBasedOnTypeof(type: 'string' | 'number' | 'undefined' | 'boolean' | 'function' | 'object' | 'symbol'): ${NODE_PREFIX}TypeAnnotation`,

packages/babel-types/scripts/generators/typescript.js

@@ -5,13 +5,10 @@ const stringifyValidator = require("../utils/stringifyValidator");
 const toFunctionName = require("../utils/toFunctionName");
 
 // For backward compat, we cannot use TS 3.7 syntax in published packages
-const ts3_7 = process.argv.includes("--ts3.7")
+const ts3_7 = process.argv.includes("--ts3.7");
-  ? (code, ...substitutions) => template(code, substitutions)
+
-  : () => "";
+// TypeScript 3.7: https://github.com/microsoft/TypeScript/pull/32695 will allow assert declarations
-const template = (strings, substitutions) =>
+const asserts = ts3_7 ? assertion => `asserts ${assertion}` : () => `boolean`;
-  strings
-    .slice(1)
-    .reduce((res, str, i) => res + substitutions[i] + str, strings[0]);
 
 let code = `// NOTE: This file is autogenerated. Do not modify.
 // See packages/babel-types/scripts/generators/typescript.js for script used.
@@ -130,24 +127,34 @@ for (const type in t.NODE_FIELDS) {
 }
 
 for (const typeName of t.TYPES) {
+  const isDeprecated = !!t.DEPRECATED_KEYS[typeName];
+  const realName = isDeprecated ? t.DEPRECATED_KEYS[typeName] : typeName;
+
   const result =
-    t.NODE_FIELDS[typeName] || t.FLIPPED_ALIAS_KEYS[typeName]
+    t.NODE_FIELDS[realName] || t.FLIPPED_ALIAS_KEYS[realName]
-      ? `node is ${typeName}`
+      ? `node is ${realName}`
       : "boolean";
 
+  if (isDeprecated) {
+    lines.push(`/** @deprecated Use \`is${realName}\` */`);
+  }
   lines.push(
-    `export function is${typeName}(node: object | null | undefined, opts?: object | null): ${result};`,
+    `export function is${typeName}(node: object | null | undefined, opts?: object | null): ${result};`
-    // TypeScript 3.7: https://github.com/microsoft/TypeScript/pull/32695 will allow assert declarations
+  );
-    // eslint-disable-next-line max-len
+
-    ts3_7`export function assert${typeName}(node: object | null | undefined, opts?: object | null): asserts ${
+  if (isDeprecated) {
+    lines.push(`/** @deprecated Use \`assert${realName}\` */`);
+  }
+  lines.push(
+    `export function assert${typeName}(node: object | null | undefined, opts?: object | null): ${asserts(
       result === "boolean" ? "node" : result
-    };`
+    )};`
   );
 }
 
 lines.push(
   // assert/
-  ts3_7`export function assertNode(obj: any): asserts obj is Node`,
+  `export function assertNode(obj: any): ${asserts("obj is Node")}`,
 
   // builders/
   // eslint-disable-next-line max-len