From 771590728e06b15a4dbf37f29c2460c5b99cdf5d Mon Sep 17 00:00:00 2001
From: Jesse Wilson <jwilson@squareup.com>
Date: Mon, 25 Mar 2024 23:20:53 -0400
Subject: [PATCH 1/2] Fix a bug where outputs weren't deterministic

This was only problematic when inputs weren't deterministic. We started
seeing this with the changes to our Gradle setup.
---
 .../com/squareup/wire/schema/LinkerTest.kt    | 51 ++++++++++++++++++-
 .../kotlin/com/squareup/wire/schema/Linker.kt |  4 ++
 2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/wire-compiler/src/test/java/com/squareup/wire/schema/LinkerTest.kt b/wire-compiler/src/test/java/com/squareup/wire/schema/LinkerTest.kt
index df836478f6..7cd2512970 100644
--- a/wire-compiler/src/test/java/com/squareup/wire/schema/LinkerTest.kt
+++ b/wire-compiler/src/test/java/com/squareup/wire/schema/LinkerTest.kt
@@ -19,6 +19,7 @@ package com.squareup.wire.schema
 
 import com.squareup.wire.testing.add
 import kotlin.test.assertFailsWith
+import okio.ForwardingFileSystem
 import okio.Path
 import okio.Path.Companion.toPath
 import okio.fakefilesystem.FakeFileSystem
@@ -480,10 +481,58 @@ class LinkerTest {
     assertThat(enumValueDeprecated!!.encodeMode).isNotNull()
   }
 
+  @Test
+  fun schemaIsDeterministicEvenIfProtoPathOrderIsNot() {
+    fs.add(
+      "source-path/a.proto",
+      """
+      |message A {
+      |}
+      """.trimMargin(),
+    )
+    fs.add(
+      "source-path/b.proto",
+      """
+      |import "a.proto";
+      |extend A {
+      |  optional string b = 1;
+      |}
+      """.trimMargin(),
+    )
+    fs.add(
+      "source-path/c.proto",
+      """
+      |import "a.proto";
+      |extend A {
+      |  optional string c = 2;
+      |}
+      """.trimMargin(),
+    )
+
+    val schemaSorted = loadAndLinkSchema()
+    assertThat((schemaSorted.getType("A") as MessageType).extensionFields.map { it.name })
+      .containsExactly("b", "c")
+
+    val schemaReversed = loadAndLinkSchema(reverseSort = true)
+    assertThat((schemaReversed.getType("A") as MessageType).extensionFields.map { it.name })
+      .containsExactly("b", "c")
+  }
+
   private fun loadAndLinkSchema(
     opaqueTypes: List<ProtoType> = listOf(),
+    reverseSort: Boolean = false,
   ): Schema {
-    val loader = SchemaLoader(fs)
+    val forwardingFileSystem = when {
+      reverseSort -> {
+        object : ForwardingFileSystem(fs) {
+          override fun listRecursively(dir: Path, followSymlinks: Boolean): Sequence<Path> =
+            super.listRecursively(dir, followSymlinks).toList().reversed().asSequence()
+        }
+      }
+      else -> fs
+    }
+
+    val loader = SchemaLoader(forwardingFileSystem)
     loader.opaqueTypes = opaqueTypes
     loader.initRoots(
       sourcePath = listOf(Location.get("source-path")),
diff --git a/wire-schema/src/commonMain/kotlin/com/squareup/wire/schema/Linker.kt b/wire-schema/src/commonMain/kotlin/com/squareup/wire/schema/Linker.kt
index e5f587c5f0..56aad8c881 100644
--- a/wire-schema/src/commonMain/kotlin/com/squareup/wire/schema/Linker.kt
+++ b/wire-schema/src/commonMain/kotlin/com/squareup/wire/schema/Linker.kt
@@ -136,6 +136,10 @@ class Linker {
       }
     }
 
+    // The order of the input files shows up in the order of extension fields in the output files.
+    // Sort the inputs to get consistent output even when the order of input files is inconsistent.
+    sourceFiles.sortBy { it.protoFile.location.path }
+
     for (fileLinker in sourceFiles) {
       fileLinker.requireTypesRegistered()
     }

From 24a10e8c04ff677a7adf2c5c926593245a42bcf5 Mon Sep 17 00:00:00 2001
From: Jesse Wilson <jwilson@squareup.com>
Date: Mon, 25 Mar 2024 23:23:53 -0400
Subject: [PATCH 2/2] Rename a local

---
 .../src/test/java/com/squareup/wire/schema/LinkerTest.kt      | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/wire-compiler/src/test/java/com/squareup/wire/schema/LinkerTest.kt b/wire-compiler/src/test/java/com/squareup/wire/schema/LinkerTest.kt
index 7cd2512970..aba242a899 100644
--- a/wire-compiler/src/test/java/com/squareup/wire/schema/LinkerTest.kt
+++ b/wire-compiler/src/test/java/com/squareup/wire/schema/LinkerTest.kt
@@ -522,7 +522,7 @@ class LinkerTest {
     opaqueTypes: List<ProtoType> = listOf(),
     reverseSort: Boolean = false,
   ): Schema {
-    val forwardingFileSystem = when {
+    val schemaLoaderFileSystem = when {
       reverseSort -> {
         object : ForwardingFileSystem(fs) {
           override fun listRecursively(dir: Path, followSymlinks: Boolean): Sequence<Path> =
@@ -532,7 +532,7 @@ class LinkerTest {
       else -> fs
     }
 
-    val loader = SchemaLoader(forwardingFileSystem)
+    val loader = SchemaLoader(schemaLoaderFileSystem)
     loader.opaqueTypes = opaqueTypes
     loader.initRoots(
       sourcePath = listOf(Location.get("source-path")),