docs: update documents-loading.mdx (#4686)

* Update documents-loading.mdx

* run prettier

* add up2date link

* Add tests for document strings

Co-authored-by: Arda TANRIKULU <[email protected]>

Author: n1ru4l

packages/load/tests/loaders/documents/documents-from-glob.spec.ts

@@ -186,5 +186,11 @@ describe('documentsFromGlob', () => {
       expect(result).toHaveLength(1);
       expect(result[0].rawSDL).toContain(pointerOptions.fooFieldName);
     });
+    test('should work only with a document string', async () => {
+      const result = await load('query { foo }', {
+        loaders: [],
+      });
+      expect(result).toHaveLength(1);
+    });
   });
 });

website/docs/documents-loading.mdx

@@ -11,7 +11,7 @@ Any input provided as a source will be recognized by utils automatically.
 
 It also extracts usages of `gql` from code files using [`@graphql-tools/graphql-tag-pluck`](/docs/graphql-tag-pluck).
 
-For notes on typescript, refer to [loaders](/docs/loaders)
+For notes on typescript, refer to [Schema Loading > Loaders](/docs/schema-loading#loaders)
 
 ## Usage
 
@@ -21,7 +21,9 @@ const { GraphQLFileLoader } = require('@graphql-tools/graphql-file-loader')
 const { CodeFileLoader } = require('@graphql-tools/code-file-loader')
 
 // load from string
-const document1 = loadDocuments('query { f }')
+const document1 = loadDocuments('query { f }', {
+  loaders: []
+})
 
 // load from a single file
 const document2 = loadDocuments('./users.query.graphql', {
@@ -52,3 +54,52 @@ interface DocumentSource {
 `loadDocuments` takes in additional configuration via the `options` object (the second argument). There are some defaults to be aware of - to learn more, see [the full API documentation](/docs/api/modules/load/#loaddocuments).
 
 > You can learn more about [loaders](/docs/loaders) to load documents from different sources.
+
+## Error handling
+
+### No files found
+
+In case no documents were found and loaded via the provided glob an exception is thrown.
+
+```ts
+import { loadDocuments } from '@graphql-tools/load'
+import { GraphQLFileLoader } from '@graphql-tools/graphql-file-loader'
+
+const documents = await loadDocuments(['i-do-not-exist.graphql'], {
+  loaders: [new GraphQLFileLoader()]
+})
+```
+
+If `i-do-not-exist.graphql` does not exist this throws the following error:
+
+```
+Error:
+      Unable to find any GraphQL type definitions for the following pointers:
+
+          - *.graphql
+```
+
+### Syntax error within a file
+
+In case you try to load a GraphQL file with invalid syntax, the `loadDocuments` function will throw a `GraphQLError`.
+
+You can identify the exact file that caused this GraphQLError by using the errors source property.
+
+```ts
+import { loadDocuments } from '@graphql-tools/load'
+import { GraphQLFileLoader } from '@graphql-tools/graphql-file-loader'
+import { CodeFileLoader } from '@graphql-tools/code-file-loader'
+import { GraphQLError } from 'graphql'
+
+try {
+  const documents = await loadDocuments(['packages/**/*.graphql', 'packages/**/*.ts(x)'], {
+    loaders: [new GraphQLFileLoader(), new CodeFileLoader()]
+  })
+  console.log(documents)
+} catch (err) {
+  if (err instanceof GraphQLError) {
+    console.log(err.message + `\n in ${err.source?.name}`)
+  }
+  throw err
+}
+```