[M] Add support for prisma.config.ts schema path (Prisma 7+)

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- [#790](https://github.com/loop-payments/prisma-lint/issues/790) Add support for Prisma 7 config file schema path configuration (`prisma.config.ts` or `.config/prisma.ts`). The `package.json#prisma.schema` field remains supported for backwards compatibility.
+
 ## 0.12.0 (2025-12-04)
 
 - [#355](https://github.com/loop-payments/prisma-lint/issues/355) Add new `/// prisma-lint-ignore-field` comment to ignore specific fields.

README.md

@@ -18,7 +18,10 @@ A linter for Prisma schema files.
 > yarn prisma-lint
 ```
 
-The default schema path is `prisma/schema.prisma`. If a custom schema path is specified in the field `prisma.schema` within `package.json`, that is used instead.
+The default schema path is `prisma/schema.prisma`. The schema path can also be configured in:
+
+1. **`prisma.config.ts`** or **`.config/prisma.ts`** (Prisma 7+): The `schema` field is used if present.
+2. **`package.json#prisma.schema`** (legacy): Supported for backwards compatibility.
 
 Alternatively, you can provide one or more explicit paths as CLI arguments. These can be globs, directories, or file paths. 
 

src/cli.ts

@@ -12,6 +12,7 @@ import { readPackageUp } from 'read-package-up';
 
 import { getTruncatedFileName } from '#src/common/file.js';
 import { parseRules } from '#src/common/parse-rules.js';
+import { getSchemaPathFromPrismaConfig } from '#src/common/prisma-config.js';
 import { lintPrismaFiles } from '#src/lint-prisma-files.js';
 import { outputToConsole } from '#src/output/console.js';
 import ruleDefinitions from '#src/rule-definitions.js';
@@ -51,6 +52,29 @@ const getSchemaFromPackageJson = async (cwd: string) => {
   return pkgJson?.packageJson?.prisma?.schema;
 };
 
+/**
+ * Gets the schema path from available configuration sources.
+ * Priority order:
+ * 1. prisma.config.ts (Prisma 7+)
+ * 2. package.json#prisma.schema (legacy, deprecated in Prisma 7)
+ * 3. null (will fall back to default)
+ */
+const getSchemaFromConfig = async (cwd: string) => {
+  // First try prisma.config.ts (Prisma 7+)
+  const schemaFromPrismaConfig = await getSchemaPathFromPrismaConfig(cwd);
+  if (schemaFromPrismaConfig != null) {
+    return schemaFromPrismaConfig;
+  }
+
+  // Fall back to package.json#prisma.schema (legacy)
+  const schemaFromPackageJson = await getSchemaFromPackageJson(cwd);
+  if (schemaFromPackageJson != null) {
+    return schemaFromPackageJson;
+  }
+
+  return null;
+};
+
 const getRootConfigResult = async () => {
   if (options.config != null) {
     const result = await explorer.load(options.config);
@@ -67,13 +91,13 @@ const getRootConfigResult = async () => {
   return result;
 };
 
-const getPathsFromArgsOrPackageJson = async (args: string[]) => {
+const getPathsFromArgsOrConfig = async (args: string[]) => {
   if (args.length > 0) {
     return args;
   }
-  const schemaFromPackageJson = await getSchemaFromPackageJson(process.cwd());
-  if (schemaFromPackageJson != null) {
-    return [schemaFromPackageJson];
+  const schemaFromConfig = await getSchemaFromConfig(process.cwd());
+  if (schemaFromConfig != null) {
+    return [schemaFromConfig];
   }
   return [DEFAULT_PRISMA_FILE_PATH];
 };
@@ -141,7 +165,7 @@ const run = async () => {
     }
   }
 
-  const paths = await getPathsFromArgsOrPackageJson(args);
+  const paths = await getPathsFromArgsOrConfig(args);
   const fileNames = resolvePrismaFileNames(paths);
   const fileViolationList = await lintPrismaFiles({
     rules,

src/common/prisma-config.test.ts

@@ -0,0 +1,217 @@
+import fs from 'fs';
+import os from 'os';
+import path from 'path';
+
+import {
+  findPrismaConfigFile,
+  getSchemaPathFromPrismaConfig,
+} from '#src/common/prisma-config.js';
+
+describe('findPrismaConfigFile', () => {
+  let tempDir: string;
+
+  beforeEach(() => {
+    tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'prisma-lint-test-'));
+  });
+
+  afterEach(() => {
+    fs.rmSync(tempDir, { recursive: true });
+  });
+
+  it('returns null when no config file exists', () => {
+    const result = findPrismaConfigFile(tempDir);
+    expect(result).toBeNull();
+  });
+
+  it('finds prisma.config.ts in current directory', () => {
+    const configPath = path.join(tempDir, 'prisma.config.ts');
+    fs.writeFileSync(configPath, 'export default {}');
+
+    const result = findPrismaConfigFile(tempDir);
+    expect(result).toBe(configPath);
+  });
+
+  it('finds prisma.config.js in current directory', () => {
+    const configPath = path.join(tempDir, 'prisma.config.js');
+    fs.writeFileSync(configPath, 'module.exports = {}');
+
+    const result = findPrismaConfigFile(tempDir);
+    expect(result).toBe(configPath);
+  });
+
+  it('finds prisma.config.mjs in current directory', () => {
+    const configPath = path.join(tempDir, 'prisma.config.mjs');
+    fs.writeFileSync(configPath, 'export default {}');
+
+    const result = findPrismaConfigFile(tempDir);
+    expect(result).toBe(configPath);
+  });
+
+  it('prefers .ts over .js', () => {
+    const tsConfigPath = path.join(tempDir, 'prisma.config.ts');
+    const jsConfigPath = path.join(tempDir, 'prisma.config.js');
+    fs.writeFileSync(tsConfigPath, 'export default {}');
+    fs.writeFileSync(jsConfigPath, 'module.exports = {}');
+
+    const result = findPrismaConfigFile(tempDir);
+    expect(result).toBe(tsConfigPath);
+  });
+
+  it('finds config in parent directory', () => {
+    const childDir = path.join(tempDir, 'child');
+    fs.mkdirSync(childDir);
+
+    const configPath = path.join(tempDir, 'prisma.config.ts');
+    fs.writeFileSync(configPath, 'export default {}');
+
+    const result = findPrismaConfigFile(childDir);
+    expect(result).toBe(configPath);
+  });
+
+  it('finds config in grandparent directory', () => {
+    const childDir = path.join(tempDir, 'child');
+    const grandchildDir = path.join(childDir, 'grandchild');
+    fs.mkdirSync(childDir);
+    fs.mkdirSync(grandchildDir);
+
+    const configPath = path.join(tempDir, 'prisma.config.ts');
+    fs.writeFileSync(configPath, 'export default {}');
+
+    const result = findPrismaConfigFile(grandchildDir);
+    expect(result).toBe(configPath);
+  });
+
+  it('finds .config/prisma.ts in current directory', () => {
+    const configDir = path.join(tempDir, '.config');
+    fs.mkdirSync(configDir);
+    const configPath = path.join(configDir, 'prisma.ts');
+    fs.writeFileSync(configPath, 'export default {}');
+
+    const result = findPrismaConfigFile(tempDir);
+    expect(result).toBe(configPath);
+  });
+
+  it('finds .config/prisma.mjs in current directory', () => {
+    const configDir = path.join(tempDir, '.config');
+    fs.mkdirSync(configDir);
+    const configPath = path.join(configDir, 'prisma.mjs');
+    fs.writeFileSync(configPath, 'export default {}');
+
+    const result = findPrismaConfigFile(tempDir);
+    expect(result).toBe(configPath);
+  });
+
+  it('prefers root-level config over .config directory', () => {
+    const rootConfigPath = path.join(tempDir, 'prisma.config.ts');
+    fs.writeFileSync(rootConfigPath, 'export default {}');
+
+    const configDir = path.join(tempDir, '.config');
+    fs.mkdirSync(configDir);
+    const dotConfigPath = path.join(configDir, 'prisma.ts');
+    fs.writeFileSync(dotConfigPath, 'export default {}');
+
+    const result = findPrismaConfigFile(tempDir);
+    expect(result).toBe(rootConfigPath);
+  });
+
+  it('finds .config/prisma.ts in parent directory', () => {
+    const childDir = path.join(tempDir, 'child');
+    fs.mkdirSync(childDir);
+
+    const configDir = path.join(tempDir, '.config');
+    fs.mkdirSync(configDir);
+    const configPath = path.join(configDir, 'prisma.ts');
+    fs.writeFileSync(configPath, 'export default {}');
+
+    const result = findPrismaConfigFile(childDir);
+    expect(result).toBe(configPath);
+  });
+});
+
+describe('getSchemaPathFromPrismaConfig', () => {
+  let tempDir: string;
+
+  beforeEach(() => {
+    tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'prisma-lint-test-'));
+  });
+
+  afterEach(() => {
+    fs.rmSync(tempDir, { recursive: true });
+  });
+
+  it('returns null when no config file exists', async () => {
+    const result = await getSchemaPathFromPrismaConfig(tempDir);
+    expect(result).toBeNull();
+  });
+
+  it('returns null when config file has no schema', async () => {
+    const configPath = path.join(tempDir, 'prisma.config.mjs');
+    fs.writeFileSync(configPath, 'export default {}');
+
+    const result = await getSchemaPathFromPrismaConfig(tempDir);
+    expect(result).toBeNull();
+  });
+
+  it('returns schema path from plain object config', async () => {
+    const configPath = path.join(tempDir, 'prisma.config.mjs');
+    fs.writeFileSync(
+      configPath,
+      "export default { schema: 'prisma/schema.prisma' }",
+    );
+
+    const result = await getSchemaPathFromPrismaConfig(tempDir);
+    expect(result).toBe(path.join(tempDir, 'prisma/schema.prisma'));
+  });
+
+  it('returns schema path from function config (defineConfig pattern)', async () => {
+    const configPath = path.join(tempDir, 'prisma.config.mjs');
+    fs.writeFileSync(
+      configPath,
+      "export default () => ({ schema: 'src/prisma/schema.prisma' })",
+    );
+
+    const result = await getSchemaPathFromPrismaConfig(tempDir);
+    expect(result).toBe(path.join(tempDir, 'src/prisma/schema.prisma'));
+  });
+
+  it('resolves relative schema path from config directory', async () => {
+    const childDir = path.join(tempDir, 'child');
+    fs.mkdirSync(childDir);
+
+    const configPath = path.join(tempDir, 'prisma.config.mjs');
+    fs.writeFileSync(
+      configPath,
+      "export default { schema: 'prisma/schema.prisma' }",
+    );
+
+    const result = await getSchemaPathFromPrismaConfig(childDir);
+    // Schema path should be relative to config file location, not cwd
+    expect(result).toBe(path.join(tempDir, 'prisma/schema.prisma'));
+  });
+
+  it('preserves absolute schema path', async () => {
+    const absoluteSchemaPath = '/absolute/path/to/schema.prisma';
+    const configPath = path.join(tempDir, 'prisma.config.mjs');
+    fs.writeFileSync(
+      configPath,
+      `export default { schema: '${absoluteSchemaPath}' }`,
+    );
+
+    const result = await getSchemaPathFromPrismaConfig(tempDir);
+    expect(result).toBe(absoluteSchemaPath);
+  });
+
+  it('returns schema path from .config/prisma.mjs', async () => {
+    const configDir = path.join(tempDir, '.config');
+    fs.mkdirSync(configDir);
+    const configPath = path.join(configDir, 'prisma.mjs');
+    fs.writeFileSync(
+      configPath,
+      "export default { schema: '../prisma/schema.prisma' }",
+    );
+
+    const result = await getSchemaPathFromPrismaConfig(tempDir);
+    // Schema path is relative to config file location (.config directory)
+    expect(result).toBe(path.join(tempDir, 'prisma/schema.prisma'));
+  });
+});