fix: partial fix for maybeSingle logging 406s

package.json

@@ -21,12 +21,13 @@
   "scripts": {
     "clean": "rimraf dist docs/v2",
     "format": "prettier --write \"{src,test}/**/*.ts\"",
+    "format:check": "prettier --check \"{src,test}/**/*.ts\"",
     "build": "run-s clean format build:*",
     "build:main": "tsc -p tsconfig.json",
     "build:module": "tsc -p tsconfig.module.json",
     "docs": "typedoc src/index.ts --out docs/v2",
     "docs:json": "typedoc --json docs/v2/spec.json --excludeExternals src/index.ts",
-    "test": "run-s test:types db:clean db:run test:run db:clean",
+    "test": "run-s format:check test:types db:clean db:run test:run db:clean",
     "test:run": "jest --runInBand",
     "test:update": "run-s db:clean db:run && jest --runInBand --updateSnapshot && run-s db:clean",
     "test:types": "run-s build:module && tsd --files test/*.test-d.ts",

src/PostgrestBuilder.ts

@@ -13,7 +13,7 @@ export default abstract class PostgrestBuilder<Result>
   protected shouldThrowOnError = false
   protected signal?: AbortSignal
   protected fetch: Fetch
-  protected allowEmpty: boolean
+  protected isMaybeSingle: boolean
 
   constructor(builder: PostgrestBuilder<Result>) {
     this.method = builder.method
@@ -23,7 +23,7 @@ export default abstract class PostgrestBuilder<Result>
     this.body = builder.body
     this.shouldThrowOnError = builder.shouldThrowOnError
     this.signal = builder.signal
-    this.allowEmpty = builder.allowEmpty
+    this.isMaybeSingle = builder.isMaybeSingle
 
     if (builder.fetch) {
       this.fetch = builder.fetch
@@ -101,6 +101,28 @@ export default abstract class PostgrestBuilder<Result>
         if (countHeader && contentRange && contentRange.length > 1) {
           count = parseInt(contentRange[1])
         }
+
+        // Temporary partial fix for https://github.com/supabase/postgrest-js/issues/361
+        // Issue persists e.g. for `.insert([...]).select().maybeSingle()`
+        if (this.isMaybeSingle && this.method === 'GET' && Array.isArray(data)) {
+          if (data.length > 1) {
+            error = {
+              // https://github.com/PostgREST/postgrest/blob/a867d79c42419af16c18c3fb019eba8df992626f/src/PostgREST/Error.hs#L553
+              code: 'PGRST116',
+              details: `Results contain ${data.length} rows, application/vnd.pgrst.object+json requires 1 row`,
+              hint: null,
+              message: 'JSON object requested, multiple (or no) rows returned',
+            }
+            data = null
+            count = null
+            status = 406
+            statusText = 'Not Acceptable'
+          } else if (data.length === 1) {
+            data = data[0]
+          } else {
+            data = null
+          }
+        }
       } else {
         const body = await res.text()
 
@@ -126,7 +148,7 @@ export default abstract class PostgrestBuilder<Result>
           }
         }
 
-        if (error && this.allowEmpty && error?.details?.includes('Results contain 0 rows')) {
+        if (error && this.isMaybeSingle && error?.details?.includes('Results contain 0 rows')) {
           error = null
           status = 200
           statusText = 'OK'

src/PostgrestTransformBuilder.ts

@@ -149,8 +149,14 @@ export default class PostgrestTransformBuilder<
   maybeSingle<
     ResultOne = Result extends (infer ResultOne)[] ? ResultOne : never
   >(): PostgrestBuilder<ResultOne | null> {
-    this.headers['Accept'] = 'application/vnd.pgrst.object+json'
-    this.allowEmpty = true
+    // Temporary partial fix for https://github.com/supabase/postgrest-js/issues/361
+    // Issue persists e.g. for `.insert([...]).select().maybeSingle()`
+    if (this.method === 'GET') {
+      this.headers['Accept'] = 'application/json'
+    } else {
+      this.headers['Accept'] = 'application/vnd.pgrst.object+json'
+    }
+    this.isMaybeSingle = true
     return this as PostgrestBuilder<ResultOne | null>
   }
 

test/transforms.ts

@@ -188,6 +188,28 @@ test('maybeSingle', async () => {
   `)
 })
 
+test('maybeSingle', async () => {
+  const res = await postgrest
+    .from('users')
+    .insert([{ username: 'a' }, { username: 'b' }])
+    .select()
+    .maybeSingle()
+  expect(res).toMatchInlineSnapshot(`
+    Object {
+      "count": null,
+      "data": null,
+      "error": Object {
+        "code": "PGRST116",
+        "details": "Results contain 2 rows, application/vnd.pgrst.object+json requires 1 row",
+        "hint": null,
+        "message": "JSON object requested, multiple (or no) rows returned",
+      },
+      "status": 406,
+      "statusText": "Not Acceptable",
+    }
+  `)
+})
+
 test('select on insert', async () => {
   const res = await postgrest.from('users').insert({ username: 'foo' }).select('status')
   expect(res).toMatchInlineSnapshot(`