From 2a8bbbcc1ac4e23dde4c449216cbf2fe64f4142f Mon Sep 17 00:00:00 2001
From: Rebecca Stevens <rebecca.stevens@outlook.co.nz>
Date: Tue, 23 Apr 2024 00:20:30 +1200
Subject: [PATCH] part: set up overridable options

---
 package.json             |  3 +-
 pnpm-lock.yaml           |  3 ++
 src/options/index.ts     |  1 +
 src/options/overrides.ts | 68 ++++++++++++++++++++++++++++++++++++++++
 src/utils/schemas.ts     | 52 ++++++++++++++++++++++++++++++
 5 files changed, 126 insertions(+), 1 deletion(-)
 create mode 100644 src/options/overrides.ts
 create mode 100644 src/utils/schemas.ts

diff --git a/package.json b/package.json
index 1db54c0a5..9f4f52fbc 100644
--- a/package.json
+++ b/package.json
@@ -74,7 +74,8 @@
     "deepmerge-ts": "^5.1.0",
     "escape-string-regexp": "^4.0.0",
     "is-immutable-type": "^3.1.0",
-    "ts-api-utils": "^1.3.0"
+    "ts-api-utils": "^1.3.0",
+    "ts-declaration-location": "^1.0.0"
   },
   "devDependencies": {
     "@babel/eslint-parser": "7.24.1",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index dbecd0e71..94347cf4c 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -23,6 +23,9 @@ importers:
       ts-api-utils:
         specifier: ^1.3.0
         version: 1.3.0(typescript@5.4.5)
+      ts-declaration-location:
+        specifier: ^1.0.0
+        version: 1.0.0(typescript@5.4.5)
     devDependencies:
       '@babel/eslint-parser':
         specifier: 7.24.1
diff --git a/src/options/index.ts b/src/options/index.ts
index a2ca8f7c3..e5b888321 100644
--- a/src/options/index.ts
+++ b/src/options/index.ts
@@ -1 +1,2 @@
 export * from "./ignore";
+export * from "./overrides";
diff --git a/src/options/overrides.ts b/src/options/overrides.ts
new file mode 100644
index 000000000..735ca2256
--- /dev/null
+++ b/src/options/overrides.ts
@@ -0,0 +1,68 @@
+import { type TSESTree } from "@typescript-eslint/utils";
+import { type RuleContext } from "@typescript-eslint/utils/ts-eslint";
+import typeMatchesSpecifier, {
+  type TypeDeclarationSpecifier,
+} from "ts-declaration-location";
+
+import { getTypeOfNode } from "../utils/rule";
+
+/**
+ * Options that can be overridden.
+ */
+export type OverridableOptions<CoreOptions> = CoreOptions & {
+  overrides?: Array<
+    {
+      specifiers: TypeDeclarationSpecifier | TypeDeclarationSpecifier[];
+    } & (
+      | {
+          options: CoreOptions;
+          disable?: false;
+        }
+      | {
+          disable: true;
+        }
+    )
+  >;
+};
+
+/**
+ * Get the core options to use, taking into account overrides.
+ *
+ * @throws when there is a configuration error.
+ */
+export function getCoreOptions<
+  CoreOptions extends object,
+  Options extends readonly [Readonly<OverridableOptions<CoreOptions>>],
+>(
+  node: TSESTree.Node,
+  context: Readonly<RuleContext<string, Options>>,
+  options: Readonly<Options>,
+): CoreOptions | null {
+  const [optionsObject] = options;
+
+  const program = context.sourceCode.parserServices?.program ?? undefined;
+  if (program === undefined) {
+    return optionsObject;
+  }
+
+  const type = getTypeOfNode(node, context);
+  const found = optionsObject.overrides?.find((override) =>
+    (Array.isArray(override.specifiers)
+      ? override.specifiers
+      : [override.specifiers]
+    ).some((specifier) => typeMatchesSpecifier(program, specifier, type)),
+  );
+
+  if (found !== undefined) {
+    if (found.disable === true) {
+      return null;
+    }
+    if (found.options === undefined) {
+      // eslint-disable-next-line functional/no-throw-statements
+      throw new Error("Configuration error: No options found for override.");
+    }
+    return found.options;
+  }
+
+  return optionsObject;
+}
diff --git a/src/utils/schemas.ts b/src/utils/schemas.ts
new file mode 100644
index 000000000..553ccaa61
--- /dev/null
+++ b/src/utils/schemas.ts
@@ -0,0 +1,52 @@
+import { type JSONSchema4 } from "@typescript-eslint/utils/json-schema";
+
+const typeSpecifierSchema: JSONSchema4 = {
+  oneOf: [
+    {
+      type: "object",
+      properties: {
+        from: {
+          type: "string",
+          enum: ["file"],
+        },
+        path: {
+          type: "string",
+        },
+      },
+      additionalProperties: false,
+    },
+    {
+      type: "object",
+      properties: {
+        from: {
+          type: "string",
+          enum: ["lib"],
+        },
+      },
+      additionalProperties: false,
+    },
+    {
+      type: "object",
+      properties: {
+        from: {
+          type: "string",
+          enum: ["package"],
+        },
+        package: {
+          type: "string",
+        },
+      },
+      additionalProperties: false,
+    },
+  ],
+};
+
+export const typeSpecifiersSchema: JSONSchema4 = {
+  oneOf: [
+    {
+      type: "array",
+      items: typeSpecifierSchema,
+    },
+    typeSpecifierSchema,
+  ],
+};