feat: first pass of adding json schema generation

moodysalem · Sep 2, 2022 · aefe97c · aefe97c
1 parent 1852e7a
commit aefe97c
Show file tree

Hide file tree

Showing 19 changed files with 279 additions and 41 deletions.
diff --git a/package.json b/package.json
@@ -62,6 +62,7 @@
   "devDependencies": {
     "@types/chai": "^4.3.3",
     "@types/mocha": "^9.1.1",
+    "ajv": "^8.11.0",
     "chai": "^4.3.6",
     "codecov": "^3.8.3",
     "conditional-type-checks": "^1.0.5",
@@ -74,5 +75,8 @@
     "ts-node": "^10.9.1",
     "typedoc": "^0.23.10",
     "typescript": "^4.7.3"
+  },
+  "dependencies": {
+    "@types/json-schema": "^7.0.11"
   }
 }
diff --git a/src/interfaces.test.ts b/src/interfaces.test.ts
@@ -1,13 +1,20 @@
 import { expect } from "chai";
 import { describe, it } from "mocha";
 import { ValidationError, Validator, FailedValidationError } from "./index";
+import { JSONSchema7 } from "json-schema";
 
 class CustomValidator extends Validator<string> {
   validate(value: any, path: Array<string> = []): ValidationError[] {
     return typeof value === "string"
       ? []
       : [{ message: "not a string", path, value }];
   }
+
+  _toJsonSchema(): JSONSchema7 {
+    return {
+      type: "string",
+    };
+  }
 }
 
 describe("Validator", () => {

diff --git a/src/interfaces.ts b/src/interfaces.ts
@@ -1,3 +1,5 @@
+import { JSONSchema4, JSONSchema7 } from "json-schema";
+
 export type ValidationErrorPath = Readonly<Array<string | number>>;
 
 /**
@@ -31,6 +33,22 @@ export class FailedValidationError extends Error {
   }
 }
 
+function removeUndefinedProperties(x: JSONSchema7): JSONSchema7 {
+  if (Array.isArray(x)) {
+    x.forEach(removeUndefinedProperties);
+    return x;
+  } else if (typeof x === "object") {
+    for (const k in x) {
+      if ((x as any)[k] === undefined) {
+        delete (x as any)[k];
+      }
+    }
+    return x;
+  } else {
+    return x;
+  }
+}
+
 /**
  * The base class of all the validators in this package. TValid is the type of any value that passes validation.
  */
@@ -45,6 +63,23 @@ export abstract class Validator<TValid> {
     path?: ValidationErrorPath
   ): ValidationError[];
 
+  private cachedJsonSchema: JSONSchema7 | undefined;
+
+  /**
+   * Handles caching and removing undefined properties
+   */
+  public toJsonSchema(): JSONSchema7 {
+    return (
+      this.cachedJsonSchema ??
+      (this.cachedJsonSchema = removeUndefinedProperties(this._toJsonSchema()))
+    );
+  }
+
+  /**
+   * Return the JSON schema for the given validator
+   */
+  protected abstract _toJsonSchema(): JSONSchema7;
+
   /**
    * Return true if the value is valid. #isValid is unique in that validation errors are not surfaced, so the validator
    * may optimize for performance.

diff --git a/src/util/check-validates.ts b/src/util/check-validates.ts
@@ -1,18 +1,23 @@
 import { ValidationError, ValidationErrorPath, Validator } from "../interfaces";
 import { expect } from "chai";
 
+import Ajv from "ajv";
+const ajv = new Ajv({});
+
 /**
  * Tests all the exposed functions of a validator, isValid, validate, and checkValid have consistent return values
  * @param validator the validator to check
  * @param value the value to validate
  * @param expectedError if invalid, these are the errors it should throw
  * @param path the path of the value being passed in
+ * @param looserJsonSchemaValidation if true, and validation fails of the validator, it is not also expected to fail for the json schema validator
  */
 export default function checkValidates(
   validator: Validator<unknown>,
   value: unknown,
   expectedError?: ValidationError[],
-  path?: ValidationErrorPath
+  path?: ValidationErrorPath,
+  looserJsonSchemaValidation: boolean = false
 ) {
   expect(validator.validate(value, path)).to.deep.eq(
     expectedError || [],
@@ -23,9 +28,17 @@ export default function checkValidates(
     return;
   }
 
-  expect(validator.isValid(value)).to.eq(
-    typeof expectedError === "undefined" || expectedError.length === 0
-  );
+  const isExpectedValid =
+    typeof expectedError === "undefined" || expectedError.length === 0;
+  expect(validator.isValid(value)).to.eq(isExpectedValid);
+
+  const schemaValidator = ajv.compile(validator.toJsonSchema());
+  schemaValidator(value);
+  if (looserJsonSchemaValidation) {
+    if (isExpectedValid) expect(!schemaValidator.errors?.length).to.eq(true);
+  } else {
+    expect(!schemaValidator.errors?.length).to.eq(isExpectedValid);
+  }
 
   if (typeof expectedError === "undefined" || expectedError.length === 0) {
     expect(() => validator.checkValid(value)).to.not.throw();

diff --git a/src/validators/any-validator.ts b/src/validators/any-validator.ts
@@ -1,4 +1,5 @@
 import { ValidationError, Validator } from "../interfaces";
+import { JSONSchema7 } from "json-schema";
 
 export default class AnyValidator extends Validator<unknown> {
   validate(
@@ -15,6 +16,10 @@ export default class AnyValidator extends Validator<unknown> {
   checkValid(value: unknown): unknown {
     return true;
   }
+
+  _toJsonSchema(): JSONSchema7 {
+    return {};
+  }
 }
 
 export const ANY_VALIDATOR = new AnyValidator();
diff --git a/src/validators/array-validator.test.ts b/src/validators/array-validator.test.ts
@@ -45,7 +45,7 @@ describe("jointz#array", () => {
     );
   });
 
-  it("validates arrays properly", () => {
+  it("validates alphanumeric string array", () => {
     checkValidates(
       jointz
         .array()
@@ -54,7 +54,9 @@ describe("jointz#array", () => {
         .items(jointz.string().alphanum().minLength(3)),
       ["abc", "123"]
     );
+  });
 
+  it("throws error for item in middle of array", () => {
     checkValidates(
       jointz.array().items(jointz.string().alphanum().minLength(3)),
       ["ab", "123"],
@@ -66,7 +68,9 @@ describe("jointz#array", () => {
         },
       ]
     );
+  });
 
+  it("can throw multiple errors from a single array", () => {
     checkValidates(
       jointz.array().items(jointz.string().alphanum().minLength(3)),
       ["a19-", "de"],

diff --git a/src/validators/array-validator.ts b/src/validators/array-validator.ts
@@ -1,3 +1,4 @@
+import { JSONSchema7 } from "json-schema";
 import { ValidationError, ValidationErrorPath, Validator } from "../interfaces";
 
 interface ArrayValidatorOptions<TItem> {
@@ -11,7 +12,6 @@ interface ArrayValidatorOptions<TItem> {
  */
 export default class ArrayValidator<TItem> extends Validator<TItem[]> {
   private readonly options: ArrayValidatorOptions<TItem>;
-
   public constructor(options: ArrayValidatorOptions<TItem>) {
     super();
     this.options = options;
@@ -105,4 +105,13 @@ export default class ArrayValidator<TItem> extends Validator<TItem[]> {
     }
     return false;
   }
+
+  public _toJsonSchema(): JSONSchema7 {
+    return {
+      type: "array",
+      minItems: this.options.minLength,
+      maxItems: this.options.maxLength,
+      items: this.options.items?.toJsonSchema(),
+    };
+  }
 }
diff --git a/src/validators/boolean-validator.ts b/src/validators/boolean-validator.ts
@@ -1,4 +1,5 @@
 import { ValidationError, ValidationErrorPath, Validator } from "../interfaces";
+import { JSONSchema7 } from "json-schema";
 
 export default class BooleanValidator extends Validator<boolean> {
   validate(value: any, path: ValidationErrorPath = []): ValidationError[] {
@@ -11,6 +12,12 @@ export default class BooleanValidator extends Validator<boolean> {
   isValid(value: any): value is boolean {
     return value === true || value === false;
   }
+
+  _toJsonSchema(): JSONSchema7 {
+    return {
+      type: "boolean",
+    };
+  }
 }
 
 export const BOOLEAN_VALIDATOR = new BooleanValidator();
diff --git a/src/validators/constant-validator.test.ts b/src/validators/constant-validator.test.ts
@@ -17,15 +17,11 @@ describe("jointz#constant", () => {
     expect(() => jointz.constant([] as any)).to.throw();
   });
 
-  it("allows null and undefined", () => {
+  it("allows null", () => {
     checkValidates(jointz.constant(null), null, []);
-    checkValidates(jointz.constant(undefined), undefined, []);
     checkValidates(jointz.constant(null), undefined, [
       { message: "must be one of null", path: [], value: undefined },
     ]);
-    checkValidates(jointz.constant(undefined), null, [
-      { message: "must be one of undefined", path: [], value: null },
-    ]);
   });
 
   it("throws with empty list", () => {

diff --git a/src/validators/constant-validator.ts b/src/validators/constant-validator.ts
@@ -1,12 +1,12 @@
 import { ValidationError, ValidationErrorPath, Validator } from "../interfaces";
+import { JSONSchema7 } from "json-schema";
 
-export type AllowedValueTypes = string | number | boolean | null | undefined;
+export type AllowedValueTypes = string | number | boolean | null;
 
 const SUPPORTED_VALUE_TYPEOF: readonly string[] = [
   "string",
   "number",
   "boolean",
-  "undefined",
 ];
 
 /**
@@ -71,4 +71,13 @@ export default class ConstantValidator<
   isValid(value: any): value is TValues[number] {
     return this.options.allowedValues.indexOf(value) !== -1;
   }
+
+  _toJsonSchema(): JSONSchema7 {
+    // todo: should we support enum here?
+    return {
+      anyOf: this.options.allowedValues.map((item) =>
+        item === null ? { type: "null" } : { const: item }
+      ),
+    };
+  }
 }
diff --git a/src/validators/json-validator.test.ts b/src/validators/json-validator.test.ts
@@ -25,27 +25,51 @@ describe("jointz#json", () => {
   });
 
   it("throws for invalid json", () => {
-    checkValidates(jointz.json(jointz.any()), '"ab', [
-      { message: "invalid json", path: [], value: '"ab' },
-    ]);
-    checkValidates(jointz.json(jointz.any()), "{", [
-      { message: "invalid json", path: [], value: "{" },
-    ]);
-    checkValidates(jointz.json(jointz.any()), "tru", [
-      { message: "invalid json", path: [], value: "tru" },
-    ]);
-    checkValidates(jointz.json(jointz.any()), "fals", [
-      { message: "invalid json", path: [], value: "fals" },
-    ]);
+    checkValidates(
+      jointz.json(jointz.any()),
+      '"ab',
+      [{ message: "invalid json", path: [], value: '"ab' }],
+      undefined,
+      true
+    );
+    checkValidates(
+      jointz.json(jointz.any()),
+      "{",
+      [{ message: "invalid json", path: [], value: "{" }],
+      undefined,
+      true
+    );
+    checkValidates(
+      jointz.json(jointz.any()),
+      "tru",
+      [{ message: "invalid json", path: [], value: "tru" }],
+      undefined,
+      true
+    );
+    checkValidates(
+      jointz.json(jointz.any()),
+      "fals",
+      [{ message: "invalid json", path: [], value: "fals" }],
+      undefined,
+      true
+    );
   });
 
   it("checks for a particular type in the json", () => {
-    checkValidates(jointz.json(jointz.boolean()), '""', [
-      { path: [], message: "must be a boolean", value: "" },
-    ]);
-    checkValidates(jointz.json(jointz.boolean()), "{}", [
-      { path: [], message: "must be a boolean", value: {} },
-    ]);
+    checkValidates(
+      jointz.json(jointz.boolean()),
+      '""',
+      [{ path: [], message: "must be a boolean", value: "" }],
+      undefined,
+      true
+    );
+    checkValidates(
+      jointz.json(jointz.boolean()),
+      "{}",
+      [{ path: [], message: "must be a boolean", value: {} }],
+      undefined,
+      true
+    );
     checkValidates(jointz.json(jointz.boolean()), "true");
     checkValidates(jointz.json(jointz.boolean()), "false");
   });

diff --git a/src/validators/json-validator.ts b/src/validators/json-validator.ts
@@ -1,4 +1,5 @@
 import { ValidationError, ValidationErrorPath, Validator } from "../interfaces";
+import { JSONSchema7 } from "json-schema";
 
 /**
  * Validates that a string contains JSON that when parsed matches the given validator
@@ -37,4 +38,13 @@ export default class JsonValidator<TParsed> extends Validator<string> {
       return false;
     }
   }
+
+  _toJsonSchema(): JSONSchema7 {
+    return {
+      type: "string",
+      contentMediaType: "application/json",
+      // next version of json schema
+      // contentSchema: this.parsedValidator.toJsonSchema(),
+    };
+  }
 }
diff --git a/src/validators/number-validator.ts b/src/validators/number-validator.ts
@@ -1,3 +1,4 @@
+import { JSONSchema7 } from "json-schema";
 import { ValidationError, ValidationErrorPath, Validator } from "../interfaces";
 
 interface NumberValidatorOptions {
@@ -8,7 +9,6 @@ interface NumberValidatorOptions {
 
 export default class NumberValidator extends Validator<number> {
   private readonly options: NumberValidatorOptions;
-
   public constructor(options: NumberValidatorOptions) {
     super();
     this.options = options;
@@ -96,4 +96,13 @@ export default class NumberValidator extends Validator<number> {
       (multipleOf === undefined || value % multipleOf === 0)
     );
   }
+
+  public _toJsonSchema(): JSONSchema7 {
+    return {
+      type: "number",
+      multipleOf: this.options.multipleOf,
+      minimum: this.options.min,
+      maximum: this.options.max,
+    };
+  }
 }