feat: add support for BinaryExpression node (#2411)

Author: srsudar

factory/parser.ts

@@ -12,6 +12,7 @@ import { AnyTypeNodeParser } from "../src/NodeParser/AnyTypeNodeParser.js";
 import { ArrayLiteralExpressionNodeParser } from "../src/NodeParser/ArrayLiteralExpressionNodeParser.js";
 import { ArrayNodeParser } from "../src/NodeParser/ArrayNodeParser.js";
 import { AsExpressionNodeParser } from "../src/NodeParser/AsExpressionNodeParser.js";
+import { BinaryExpressionNodeParser } from "../src/NodeParser/BinaryExpressionNodeParser.js";
 import { BooleanLiteralNodeParser } from "../src/NodeParser/BooleanLiteralNodeParser.js";
 import { BooleanTypeNodeParser } from "../src/NodeParser/BooleanTypeNodeParser.js";
 import { CallExpressionParser } from "../src/NodeParser/CallExpressionParser.js";
@@ -118,6 +119,7 @@ export function createParser(program: ts.Program, config: CompletedConfig, augme
         .addNodeParser(new NeverTypeNodeParser())
         .addNodeParser(new ObjectTypeNodeParser())
         .addNodeParser(new AsExpressionNodeParser(chainNodeParser))
+        .addNodeParser(new BinaryExpressionNodeParser(chainNodeParser))
         .addNodeParser(new SatisfiesNodeParser(chainNodeParser))
         .addNodeParser(withJsDoc(new ParameterParser(chainNodeParser)))
         .addNodeParser(new StringLiteralNodeParser())

package.json

@@ -50,6 +50,7 @@
     "release": "npm run build && auto shipit",
     "run": "tsx ts-json-schema-generator.ts",
     "test": "jest test/ --verbose",
+    "test:debug": "node --inspect-brk node_modules/.bin/jest test/ --verbose --runInBand",
     "test:coverage": "npm run jest -- test/ --collectCoverage=true",
     "test:fast": "cross-env FAST_TEST=1 jest test/ --verbose",
     "test:update": "cross-env UPDATE_SCHEMA=true npm run test:fast",

src/NodeParser/BinaryExpressionNodeParser.ts

@@ -0,0 +1,99 @@
+import ts from "typescript";
+import type { Context, NodeParser } from "../NodeParser.js";
+import type { SubNodeParser } from "../SubNodeParser.js";
+import { AnyType } from "../Type/AnyType.js";
+import type { BaseType } from "../Type/BaseType.js";
+import { BooleanType } from "../Type/BooleanType.js";
+import { LiteralType } from "../Type/LiteralType.js";
+import { NumberType } from "../Type/NumberType.js";
+import { StringType } from "../Type/StringType.js";
+import { UnionType } from "../Type/UnionType.js";
+import { AliasType } from "../Type/AliasType.js";
+
+export class BinaryExpressionNodeParser implements SubNodeParser {
+    public constructor(protected childNodeParser: NodeParser) {}
+
+    public supportsNode(node: ts.Node): boolean {
+        return node.kind === ts.SyntaxKind.BinaryExpression;
+    }
+
+    public createType(node: ts.BinaryExpression, context: Context): BaseType {
+        const leftType = this.childNodeParser.createType(node.left, context);
+        const rightType = this.childNodeParser.createType(node.right, context);
+
+        if (leftType instanceof AnyType || rightType instanceof AnyType) {
+            return new AnyType();
+        }
+
+        if (this.isStringLike(leftType) || this.isStringLike(rightType)) {
+            return new StringType();
+        }
+
+        if (this.isDefinitelyNumberLike(leftType) && this.isDefinitelyNumberLike(rightType)) {
+            return new NumberType();
+        }
+
+        if (this.isBooleanLike(leftType) && this.isBooleanLike(rightType)) {
+            return new BooleanType();
+        }
+
+        // Anything else (objects, any, unknown, weird unions, etc.) return
+        // 'string' because at runtime + will usually go through ToPrimitive and
+        // end up in the "string concatenation" branch when non-numeric stuff is
+        // involved.
+        return new StringType();
+    }
+
+    private isStringLike(type: BaseType): boolean {
+        if (type instanceof AliasType) {
+            return this.isStringLike(type.getType());
+        }
+
+        if (type instanceof StringType) {
+            return true;
+        }
+
+        if (type instanceof LiteralType && type.isString()) {
+            return true;
+        }
+
+        // Any union member being string-like is enough.
+        if (type instanceof UnionType) {
+            return type.getTypes().some((t) => this.isStringLike(t));
+        }
+
+        return false;
+    }
+
+    private isBooleanLike(type: BaseType): boolean {
+        if (type instanceof BooleanType) {
+            return true;
+        }
+
+        if (type instanceof LiteralType && typeof type.getValue() === "boolean") {
+            return true;
+        }
+
+        return false;
+    }
+
+    private isDefinitelyNumberLike(type: BaseType): boolean {
+        if (type instanceof AliasType) {
+            return this.isDefinitelyNumberLike(type.getType());
+        }
+
+        if (type instanceof NumberType) {
+            return true;
+        }
+
+        if (type instanceof LiteralType && typeof type.getValue() === "number") {
+            return true;
+        }
+
+        if (type instanceof UnionType) {
+            return type.getTypes().every((t) => this.isDefinitelyNumberLike(t));
+        }
+
+        return false;
+    }
+}

test/valid-data-type.test.ts

@@ -9,6 +9,7 @@ describe("valid-data-type", () => {
     it("type-aliases-object", assertValidSchema("type-aliases-object", "MyAlias"));
     it("type-aliases-mixed", assertValidSchema("type-aliases-mixed", "MyObject"));
     it("type-aliases-union", assertValidSchema("type-aliases-union", "MyUnion"));
+    it("binary-expression", assertValidSchema("binary-expression", "MyObject"));
     it("type-aliases-anonymous", assertValidSchema("type-aliases-anonymous", "MyObject"));
     it("type-aliases-local-namespace", assertValidSchema("type-aliases-local-namespace", "MyObject"));
     it("type-aliases-recursive-anonymous", assertValidSchema("type-aliases-recursive-anonymous", "MyAlias"));

test/valid-data/binary-expression/main.ts

@@ -0,0 +1,66 @@
+type StringUnion = "a" | "b";
+type NumberUnion = 10 | 20;
+type MixedUnion = "c" | 30;
+
+function getAny(): any {
+    return "test" as any;
+}
+
+function getBoolean(): boolean {
+    return Math.random() > 0.5;
+}
+
+function getStringUnion(): StringUnion {
+    return Math.random() > 0.5 ? "a" : "b";
+}
+
+function getNumberUnion(): NumberUnion {
+    return Math.random() > 0.5 ? 10 : 20;
+}
+
+function getMixedUnion(): MixedUnion {
+    return Math.random() > 0.5 ? "c" : 30;
+}
+
+function getUnknown(): unknown {
+    return "unknown value";
+}
+
+function getStringType(): string {
+    return Math.random() > 0.5 ? "hello" : "world";
+}
+
+const anyString: any = getAny();
+
+const aStringUnion: StringUnion = getStringUnion();
+const bStringUnion: StringUnion = getStringUnion();
+
+const tenNumberUnion: NumberUnion = getNumberUnion();
+const twentyNumberUnion: NumberUnion = getNumberUnion();
+
+const thirtyMixedUnion: MixedUnion = getMixedUnion();
+
+const a: boolean = getBoolean();
+const b: boolean = getBoolean();
+
+const unknownValue: unknown = getUnknown();
+
+const foo = {
+    numbers: 60 * 5,
+    stringLiterals: "a" + "b",
+    stringTypes: getStringType() + getStringType(),
+    booleanTypes: a || b,
+    booleanLiterals: true || false,
+    any: 1 + anyString,
+    threeNumbers: 60 * 5 + 1,
+    mixedStringAndNumbers: 60 * 5 + " minutes",
+    bigintType: BigInt(123),
+
+    unknowns: unknownValue && unknownValue,
+
+    stringUnion: aStringUnion + bStringUnion,
+    numberUnion: tenNumberUnion + twentyNumberUnion,
+    mixedUnion: thirtyMixedUnion + " is a number",
+} as const;
+
+export type MyObject = typeof foo;

test/valid-data/binary-expression/schema.json

@@ -0,0 +1,40 @@
+{
+  "$ref": "#/definitions/MyObject",
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "definitions": {
+    "MyObject": {
+      "additionalProperties": false,
+      "properties": {
+        "numbers": { "type": "number" },
+        "threeNumbers": { "type": "number" },
+        "stringLiterals": { "type": "string" },
+        "stringTypes": { "type": "string" },
+        "mixedStringAndNumbers": { "type": "string" },
+        "booleanTypes": { "type": "boolean" },
+        "booleanLiterals": { "type": "boolean" },
+        "bigintType": { "type": "number" },
+        "numberUnion": { "type": "number" },
+        "stringUnion": { "type": "string" },
+        "unknowns": { "type": "string" },
+        "mixedUnion": { "type": "string" },
+        "any": {}
+      },
+      "required": [
+        "numbers",
+        "stringLiterals",
+        "stringTypes",
+        "booleanTypes",
+        "booleanLiterals",
+        "any",
+        "threeNumbers",
+        "mixedStringAndNumbers",
+        "bigintType",
+        "unknowns",
+        "stringUnion",
+        "numberUnion",
+        "mixedUnion"
+      ],
+      "type": "object"
+    }
+  }
+}