fix: use import id @prisma/client by default when possible

package.json

@@ -32,7 +32,7 @@
     "build:module-facades": "ts-node scripts/build-module-facades",
     "build": "yarn clean && yarn build:module-facades && tsc",
     "test": "cross-env DEBUG=e2e jest",
-    "test:ci": "cross-env DEBUG=e2e jest --coverage --forceExit --runInBand",
+    "test:ci": "cross-env DEBUG='e2e' jest --coverage --forceExit --runInBand",
     "tdd": "jest --watch",
     "tdd:e2e:debug": "cross-env test_project_reuse=true jest --watch e2e",
     "clean": "rm -rf dist && rm -rf node_modules/.cache",

src/cli/nexus-prisma.ts

@@ -4,11 +4,12 @@
 
 process.env.DEBUG_COLORS = 'true'
 process.env.DEBUG_HIDE_DATE = 'true'
-import { generatorHandler } from '@prisma/generator-helper'
+import { GeneratorConfig, generatorHandler } from '@prisma/generator-helper'
 import * as Path from 'path'
 import { generateRuntimeAndEmit } from '../generator'
 import { loadUserGentimeSettings } from '../generator/gentime/settingsLoader'
 import { Gentime } from '../generator/gentime/settingsSingleton'
+import { d } from '../helpers/debugNexusPrisma'
 import { externalToInternalDmmf } from '../helpers/prismaExternalToInternalDMMF'
 
 // todo by default error in ci and warn in local
@@ -28,13 +29,19 @@ generatorHandler({
   async onGenerate({ dmmf, otherGenerators }) {
     const prismaClientGenerator = otherGenerators.find((g) => g.provider.value === 'prisma-client-js')
 
+    // TODO test showing this pretty error in action
+    if (!prismaClientGenerator) {
+      // TODO consider a prisma-client-less mode
+      throw new Error(
+        `Nexus Prisma cannot be used without Prisma Client. Please add it to your Prisma Schema file.`
+      )
+    }
+
     // WARNING: Make sure this logic comes before `loadUserGentimeSettings` below
     // otherwise we will overwrite the user's choice for this setting if they have set it.
-    if (prismaClientGenerator?.output?.value) {
-      Gentime.settings.change({
-        prismaClientImportId: prismaClientGenerator.output.value,
-      })
-    }
+    Gentime.settings.change({
+      prismaClientImportId: getPrismaClientImportIdForItsGeneratorOutputConfig(prismaClientGenerator),
+    })
 
     const internalDMMF = externalToInternalDmmf(dmmf)
     loadUserGentimeSettings()
@@ -44,3 +51,78 @@ generatorHandler({
     )
   },
 })
+
+/**
+ * Hehlpers
+ */
+
+/**
+ * Get the appropiate import ID for Prisma Client.
+ *
+ * When generator output is set to its default location within node_modules, then we return the import ID of just its npm moniker "@prisma/client".
+ *
+ * Othewise we return an import ID as an absolute path to the output location.
+ */
+function getPrismaClientImportIdForItsGeneratorOutputConfig(
+  prismaClientGeneratorConfig: GeneratorConfig
+): string {
+  const prismaClientPackageMoniker = `@prisma/client`
+  const prismaClientPackagePath = Path.join(`@prisma`, `client`)
+
+  if (!prismaClientGeneratorConfig.output || !prismaClientGeneratorConfig.output.value) {
+    return prismaClientPackageMoniker
+  }
+
+  if (prismaClientGeneratorConfig.output.value.endsWith(prismaClientPackagePath)) {
+    /**
+     * Goal of this code:
+     *
+     * Find out if we can import Prisma Client by simplify specifying its moniker (@prisma/client).
+     *
+     * Why do we want to import by Moniker? Because it is a good default because it is what a user would
+     * do in their own code. Also because not doing so has led to bugs https://github.com/prisma/nexus-prisma/issues/76.
+     *
+     * How this works:
+     *
+     * 1. Get the Prisma Client generatour output path minus the trailing node_moudles/@prisma/client (if present, it could be totally custom).
+     *
+     * Note that even if the user has not explicitly configured an output path in their PSL file by the time we get the geneator config from
+     * Prisma generator system the output default has been supplied so we always have a value here to work with.
+     *
+     * 2. Get the Nexus Prisma package path on the user's machine by starting from this module and going four directories up. Four directories
+     * up goes above the node_modules directory into their code.
+     *
+     * Note that we must go four up, not three up (which would be node_modules), because when using Yalc (used for development and E2E tests)
+     * Nexus Prisma is placed into <project>/.yalc rather than <project>/node_modules. And therefore, the check we want to achieve here would
+     * fail when it shouldn't.
+     *
+     * 3. With the two paths we check what the relative path between them is. If its an empty string, it means they are the same.
+     *
+     * Note this technique is better than string comparison because it guards against meaningless path difference details like windows vs posix.
+     * We're not certain what path standard we'll get from Prisma for example and ideally we don't care. Path.relative function should let us not
+     * care.
+     */
+    const dirPrismaClientOutputWithoutTrailingNodeModulesMoniker =
+      prismaClientGeneratorConfig.output.value.replace(
+        new RegExp(`${Path.join('node_modules', prismaClientPackagePath)}$`),
+        ''
+      )
+    const dirProjectForThisNexusPrisma = Path.join(__dirname, '../../../..')
+    const dirDiff = Path.relative(
+      dirPrismaClientOutputWithoutTrailingNodeModulesMoniker,
+      dirProjectForThisNexusPrisma
+    )
+
+    d(`found prisma client/nexus prisma layout:`, {
+      dirPrismaClientOutputWithoutTrailingNodeModulesMoniker,
+      dirProjectForThisNexusPrisma,
+      dirDiff,
+    })
+
+    if (dirDiff === '') {
+      return prismaClientPackageMoniker
+    }
+  }
+
+  return prismaClientGeneratorConfig.output.value
+}

src/helpers/prisma.ts

@@ -8,6 +8,7 @@ import kleur = require('kleur')
 
 export const getPrismaClientDmmf = (importId = '@prisma/client'): DMMF.Document => {
   d('get dmmf from @prisma/client')
+  console.log(importId)
 
   let maybeDmmf: DMMF.Document | undefined
 

tests/e2e/e2e.test.ts

@@ -60,7 +60,7 @@ function setupTestNexusPrismaProject(): TestProject {
       license: 'MIT',
       scripts: {
         reflect: 'yarn -s reflect:prisma && yarn -s reflect:nexus',
-        'reflect:prisma': 'prisma generate',
+        'reflect:prisma': "cross-env DEBUG='*' prisma generate",
         // peer dependency check will fail since we're using yalc, e.g.:
         // " ... nexus-prisma@0.0.0-dripip+c2653557 does not officially support @prisma/client@2.22.1 ... "
         'reflect:nexus': 'cross-env REFLECT=true ts-node --transpile-only src/schema',
@@ -334,6 +334,14 @@ it('When bundled custom scalars are used the project type checks and generates e
 
   expect(results.fileTypegen).toMatchSnapshot('nexus typegen')
 
+  /**
+   * Sanity check the Prisma Client import ID
+   */
+
+  expect(testProject.fs.read('node_modules/nexus-prisma/dist/runtime/index.js')).toMatch(
+    /.*"prismaClientImportId": "@prisma\/client".*/
+  )
+
   /**
    * Sanity check the runtime
    */