add field transform (#83)

odama626 · tonyketcham · web-flow · commit fe76ae19c9ac · 2022-08-12T00:20:09.000-05:00
* add field transform

* Update README.md

Co-authored-by: Tony &lt;tonyketcham@gmail.com&gt;

* comments

* fix type name

* comments

* formatting

* add prepare script

* remove prepare script

* undo toLowerCase

Co-authored-by: Tony &lt;tonyketcham@gmail.com&gt;
diff --git a/packages/core/src/errors.ts b/packages/core/src/errors.ts
@@ -0,0 +1,18 @@
+import { outdent } from './utils/outdent';
+
+export class IllegalFieldNameError extends Error {
+  constructor(illegalSequence: string) {
+    super();
+    this.message = outdent`
+      The sequence "${illegalSequence}" is reserved and not allowed in field names
+      Either:
+        - remove all instances of "${illegalSequence}" in the names of fields in your content
+        - add a fieldNameTransform function to your flatbread.config.js to translate to something else
+          Example:
+            {
+              ...,
+              fieldNameTransform: (value) => value.replaceAll("${illegalSequence}",'-')
+            }
+      `;
+  }
+}
diff --git a/packages/core/src/generators/generateCollection.ts b/packages/core/src/generators/generateCollection.ts
@@ -0,0 +1,27 @@
+import { defaultsDeep, merge } from 'lodash-es';
+import { LoadedFlatbreadConfig } from '../types';
+import { getFieldOverrides } from '../utils/fieldOverrides';
+import transformKeys from '../utils/transformKeys';
+
+interface GenerateCollectionArgs<T> {
+  collection: string;
+  nodes: T[];
+  config: LoadedFlatbreadConfig;
+  preknownSchemaFragments: Record<string, any[]>;
+}
+
+export function generateCollection<T>({
+  collection,
+  preknownSchemaFragments,
+  config,
+  nodes,
+}: GenerateCollectionArgs<T>) {
+  return transformKeys(
+    defaultsDeep(
+      {},
+      getFieldOverrides(collection, config),
+      ...nodes.map((node) => merge({}, node, preknownSchemaFragments))
+    ),
+    config.fieldNameTransform
+  );
+}
diff --git a/packages/core/src/generators/schema.ts b/packages/core/src/generators/schema.ts
@@ -1,23 +1,23 @@
 import { schemaComposer } from 'graphql-compose';
 import { composeWithJson } from 'graphql-compose-json';
-import { cloneDeep, defaultsDeep, merge } from 'lodash-es';
+import { cloneDeep, merge } from 'lodash-es';
 import plur from 'plur';
 import { VFile } from 'vfile';
+import { cacheSchema, checkCacheForSchema } from '../cache/cache';
 import {
   generateArgsForAllItemQuery,
   generateArgsForManyItemQuery,
   generateArgsForSingleItemQuery,
 } from '../generators/arguments';
 import resolveQueryArgs from '../resolvers/arguments';
-import { cacheSchema, checkCacheForSchema } from '../cache/cache';
 import {
   ConfigResult,
   EntryNode,
   LoadedFlatbreadConfig,
   Transformer,
 } from '../types';
 import { map } from '../utils/map';
-import { getFieldOverrides } from '../utils/fieldOverrides';
+import { generateCollection } from './generateCollection';
 
 interface RootQueries {
   maybeReturnsSingleItem: string[];
@@ -69,11 +69,12 @@ export async function generateSchema(
       collection,
       composeWithJson(
         collection,
-        defaultsDeep(
-          {},
-          getFieldOverrides(collection, config),
-          ...nodes.map((node) => merge({}, node, preknownSchemaFragments))
-        ),
+        generateCollection({
+          collection,
+          nodes,
+          config,
+          preknownSchemaFragments,
+        }),
         { schemaComposer }
       ),
     ])
diff --git a/packages/core/src/types.ts b/packages/core/src/types.ts
@@ -24,12 +24,14 @@ export interface FlatbreadConfig {
   source: Source;
   transformer?: Transformer | Transformer[];
   content: Content;
+  fieldNameTransform?: (field: string) => string;
 }
 
 export interface LoadedFlatbreadConfig {
   source: Source;
   transformer: Transformer[];
   content: Content;
+  fieldNameTransform: (field: string) => string;
   loaded: {
     extensions: string[];
   };
diff --git a/packages/core/src/utils/camelCase.ts b/packages/core/src/utils/camelCase.ts
@@ -0,0 +1,8 @@
+/**
+ * camelCase string
+ * @param field: string
+ * @returns camelCaseString
+ */
+export default function camelCase(field: string) {
+  return String(field).replace(/\s(\w)/g, (_, m) => m.toUpperCase());
+}
diff --git a/packages/core/src/utils/initializeConfig.ts b/packages/core/src/utils/initializeConfig.ts
@@ -1,6 +1,7 @@
 import { cloneDeep } from 'lodash-es';
 import { FlatbreadConfig, LoadedFlatbreadConfig, Transformer } from '../types';
 import { toArray } from './arrayUtils';
+import camelCase from './camelCase';
 
 /**
  * Processes a config object and returns a normalized version of it.
@@ -11,7 +12,8 @@ export function initializeConfig(
   const config = cloneDeep(rawConfig);
   const transformer = toArray(config.transformer ?? []);
 
-  const newConfig = {
+  return {
+    fieldNameTransform: camelCase,
     ...config,
     transformer,
     loaded: {
@@ -20,6 +22,4 @@ export function initializeConfig(
         .flat(),
     },
   };
-
-  return newConfig;
 }
diff --git a/packages/core/src/utils/objectUtils.ts b/packages/core/src/utils/objectUtils.ts
@@ -0,0 +1,7 @@
+export function isObject<K extends string | number | symbol, T>(
+  value: unknown
+): value is Record<K, T> {
+  return (
+    !!value && typeof value === 'object' && value.constructor.name === 'Object'
+  );
+}
diff --git a/packages/core/src/utils/outdent.ts b/packages/core/src/utils/outdent.ts
@@ -0,0 +1,21 @@
+/**
+ * when used as a template literal tag will remove the indentation that exists from the code block indentation
+ *
+ */
+
+export function outdent(
+  strings: TemplateStringsArray,
+  ...values: string[]
+): string {
+  const result = strings
+    .map((s, i) => s + (values[i] ?? ''))
+    .join('')
+    .trim();
+  const matches = Array.from(result.matchAll(/\n(\s+)/gs));
+  const minimumIndent =
+    matches.map((match) => match[1]).sort((a, b) => a.length - b.length)?.[0]
+      ?.length ?? 0;
+  const replacer = new RegExp(`\\n\\s{${minimumIndent}}`, 'g');
+
+  return result.replace(replacer, '\n');
+}
diff --git a/packages/core/src/utils/tests/outdent.test.ts b/packages/core/src/utils/tests/outdent.test.ts
@@ -0,0 +1,37 @@
+import test from 'ava';
+import { outdent } from '../outdent';
+
+test('basic outdent', (t) => {
+  const result = outdent`This
+  is
+  a
+  test you
+    this should still be indented`;
+
+  t.is(
+    result,
+    `This
+is
+a
+test you
+  this should still be indented`
+  );
+});
+
+test('it still interpolates data', (t) => {
+  const p = 'animal';
+  const result = outdent`This
+  is
+  a
+  test you ${p}
+    this should still be indented`;
+
+  t.is(
+    result,
+    `This
+is
+a
+test you animal
+  this should still be indented`
+  );
+});
diff --git a/packages/core/src/utils/tests/snapshots/transformKeys.test.ts.md b/packages/core/src/utils/tests/snapshots/transformKeys.test.ts.md
@@ -0,0 +1,19 @@
+# Snapshot report for `packages/core/src/utils/tests/transformKeys.test.ts`
+
+The actual snapshot is saved in `transformKeys.test.ts.snap`.
+
+Generated by [AVA](https://avajs.dev).
+
+## it throws an error on illegal field names
+
+> Snapshot 1
+
+    `The sequence "[]" is reserved and not allowed in field names␊
+    Either:␊
+      - remove all instances of "[]" in the names of fields in your content␊
+      - add a fieldTransform function to your flatbread.config.js to translate to something else␊
+        Example:␊
+          {␊
+            ...,␊
+            fieldTransform: (value) => value.replaceAll("[]",'-')␊
+          }`
diff --git a/packages/core/src/utils/tests/snapshots/transformKeys.test.ts.snap b/packages/core/src/utils/tests/snapshots/transformKeys.test.ts.snap
diff --git a/packages/core/src/utils/tests/transformKeys.test.ts b/packages/core/src/utils/tests/transformKeys.test.ts
@@ -0,0 +1,66 @@
+import test from 'ava';
+import { camelCase } from 'lodash-es';
+import transformKeys from '../transformKeys';
+
+test('it works for basic entries', (t) => {
+  t.deepEqual(
+    transformKeys({ 'this is a test': true, blah: 'blah' }, camelCase),
+    {
+      thisIsATest: true,
+      blah: 'blah',
+    }
+  );
+
+  t.deepEqual(
+    transformKeys({ 'this is a test': [1, 2, 3, 4], blah: 'blah' }, camelCase),
+    {
+      thisIsATest: [1, 2, 3, 4],
+      blah: 'blah',
+    }
+  );
+});
+
+test('it works with arrays', (t) => {
+  t.deepEqual(
+    transformKeys({ 'this is a test': [1, 2, 3, 4], blah: 'blah' }, camelCase),
+    {
+      thisIsATest: [1, 2, 3, 4],
+      blah: 'blah',
+    }
+  );
+});
+
+test('it works with undescores', (t) => {
+  t.deepEqual(
+    transformKeys({ this_is_a_test: [1, 2, 3, 4], blah: 'blah' }, camelCase),
+    {
+      thisIsATest: [1, 2, 3, 4],
+      blah: 'blah',
+    }
+  );
+});
+
+test('it works with dates', (t) => {
+  t.deepEqual(
+    transformKeys(
+      { this_is_a_test: new Date('2021-02-25T16:41:59.558Z'), blah: 'blah' },
+      camelCase
+    ),
+    {
+      thisIsATest: new Date('2021-02-25T16:41:59.558Z'),
+      blah: 'blah',
+    }
+  );
+});
+
+test('it throws an error on illegal field names', (t) => {
+  const error = t.throws(() =>
+    transformKeys(
+      {
+        'thisisatest[]': test,
+      },
+      (s) => s
+    )
+  );
+  t.snapshot(error?.message);
+});
diff --git a/packages/core/src/utils/transformKeys.ts b/packages/core/src/utils/transformKeys.ts
@@ -0,0 +1,38 @@
+import { outdent } from './outdent';
+
+class IllegalFieldNameError extends Error {
+  constructor(illegalSequence: string) {
+    super();
+    this.message = outdent`
+      The sequence "${illegalSequence}" is reserved and not allowed in field names
+      Either:
+        - remove all instances of "${illegalSequence}" in the names of fields in your content
+        - add a fieldTransform function to your flatbread.config.js to translate to something else
+          Example:
+            {
+              ...,
+              fieldTransform: (value) => value.replaceAll("${illegalSequence}",'-')
+            }
+      `;
+  }
+}
+
+function isObject(obj: any): obj is Object {
+  return obj != null && obj.constructor.name === 'Object';
+}
+
+export default function transformKeys(
+  obj: any,
+  transform: (key: string) => string
+): any {
+  if (Array.isArray(obj))
+    return obj.map((item) => transformKeys(item, transform));
+  if (!isObject(obj)) return obj;
+  return Object.fromEntries(
+    Object.entries(obj).map(([key, value]) => {
+      const newKey = transform(key);
+      if (newKey.includes('[]')) throw new IllegalFieldNameError('[]');
+      return [newKey, transformKeys(value, transform)];
+    })
+  );
+}
diff --git a/packages/flatbread/README.md b/packages/flatbread/README.md
@@ -294,6 +294,20 @@ Field overrides allow you to define custom GraphQL types or resolvers on top of
 
 for more information in Overrides, they adhere to the GraphQLFieldConfig outlined here https://graphql-compose.github.io/docs/basics/what-is-resolver.html
 
+## Advanced Config
+
+### `fieldNameTransform`
+
+Accepts a function which takes in field names and transforms them for the GraphQL schema generation -- this is used internally to remove spaces but can be used for other global transforms as well
+
+````js
+{
+  ...
+  // replace all spaces in field names with an underscore
+  fieldNameTransform: (fieldName) => field.name.replace(/\s/g,'_')
+  ...
+}
+
 # ☀️ Contributing
 
 You're encouraged to [join our Slack](https://join.slack.com/t/flatbreadworkspace/shared_invite/zt-1bvnhr38j-oHFun85aGfaNp9qwizOORw) and ask questions! Let us know if anything is unclear - if so, that just means we need to improve our docs 😁 We can help set you off on the right foot so you don't feel like you're flying blind.
@@ -310,7 +324,7 @@ You may need to seed this with a `pnpm build` first, as there can be a race cond
 
 ```bash
 pnpm dev
-```
+````
 
 ## **working on a package** ⚒️
 
