test(manifest): add Kotlin Multiplatform fixture for --facts

A minimal KMP project (jvm + js targets) exercises per-target compile
and runtime classpaths (jvmMainCompileClasspath, jsTestRuntimeClasspath,
...) that aren't surfaced through Java's SourceSetContainer. Our
name-pattern selection picks them up by suffix.

The fixture pulls kotlinx-serialization-core (commonMain) so it shows
up in both jvm and js target variants of the artifact, and slf4j-api
(jvmMain-only) to confirm target-specific classpaths flow through. The
test asserts both deps are present in the resulting components array.

Author: jfblaa

src/commands/manifest/socket-facts-init-gradle.e2e.test.mts

@@ -181,6 +181,36 @@ describeOrSkip('socket-facts.init.gradle', () => {
     })
   })
 
+  describe('kotlin-multiplatform fixture', () => {
+    const fixture = path.join(fixturesRoot, 'kotlin-multiplatform')
+    const output = path.join(fixture, '.socket.facts.json')
+
+    it('captures per-target classpaths from kotlin.targets', async () => {
+      clean(output)
+      await runFacts(fixture)
+      expect(existsSync(output)).toBe(true)
+      const facts = readFacts(output)
+      // commonMain dep — should resolve into both jvm and js target variants.
+      const serializationCore = findById(
+        facts,
+        c =>
+          c.namespace === 'org.jetbrains.kotlinx' &&
+          c.name.startsWith('kotlinx-serialization-core'),
+      )
+      expect(
+        serializationCore.length,
+        `expected kotlinx-serialization-core in at least one target variant: ${facts.components.map(c => c.id).join(', ')}`,
+      ).toBeGreaterThan(0)
+      // jvmMain-only dep — should be present, exercising the per-target
+      // classpath name pattern (`jvmMainRuntimeClasspath` and friends).
+      const slf4j = findById(
+        facts,
+        c => c.namespace === 'org.slf4j' && c.name === 'slf4j-api',
+      )
+      expect(slf4j.length, 'jvmMain slf4j-api present').toBeGreaterThan(0)
+    })
+  })
+
   describe('android-library fixture', () => {
     const fixture = path.join(fixturesRoot, 'android-library')
     const output = path.join(fixture, '.socket.facts.json')

test/fixtures/commands/manifest/gradle-facts/kotlin-multiplatform/build.gradle

@@ -0,0 +1,35 @@
+// Kotlin Multiplatform fixture for socket-facts.init.gradle. Exercises
+// per-target compile/runtime configurations (jvmMainCompileClasspath,
+// jsTestRuntimeClasspath, etc.) that the Java SourceSetContainer doesn't
+// surface, but which our name-pattern selection (`*CompileClasspath` /
+// `*RuntimeClasspath`) still picks up.
+plugins {
+    id 'org.jetbrains.kotlin.multiplatform' version '1.9.25'
+}
+
+group = 'com.example.socket.kmp'
+version = '1.0.0'
+
+repositories {
+    mavenCentral()
+}
+
+kotlin {
+    jvm()
+    js {
+        nodejs()
+    }
+
+    sourceSets {
+        commonMain {
+            dependencies {
+                implementation 'org.jetbrains.kotlinx:kotlinx-serialization-core:1.6.2'
+            }
+        }
+        jvmMain {
+            dependencies {
+                implementation 'org.slf4j:slf4j-api:1.7.36'
+            }
+        }
+    }
+}

test/fixtures/commands/manifest/gradle-facts/kotlin-multiplatform/settings.gradle

@@ -0,0 +1,9 @@
+pluginManagement {
+    repositories {
+        gradlePluginPortal()
+        mavenCentral()
+        google()
+    }
+}
+
+rootProject.name = 'kotlin-multiplatform'