fix(all): forward --pathmap: option to FCS so CallerFilePath respects (PathMap)

src/Fable.Compiler/ProjectCracker.fs

@@ -438,6 +438,9 @@ let private extractUsefulOptionsAndSources
         // Only forward the nullness flag if it is coming from the main project
         elif line.StartsWith("--checknulls+", StringComparison.Ordinal) && isMainProj then
             accSources, line :: accOptions
+        // Forward pathmap from the main project so CallerFilePath respects <PathMap>/<DeterministicSourcePaths>
+        elif line.StartsWith("--pathmap:", StringComparison.Ordinal) && isMainProj then
+            accSources, line :: accOptions
         elif
             line.StartsWith("--nowarn", StringComparison.Ordinal)
             || line.StartsWith("--warnon", StringComparison.Ordinal)

tests/Integration/Integration/data/pathMap/CallerFilePathTest.fs

@@ -0,0 +1,14 @@
+module CallerFilePathTest
+
+open System.Runtime.CompilerServices
+open System.Runtime.InteropServices
+
+type Log =
+    static member info
+        (
+            message: string,
+            [<CallerFilePath; Optional; DefaultParameterValue("")>] path: string
+        ) =
+        printfn "%s: %s" path message
+
+Log.info "hello"

tests/Integration/Integration/data/pathMap/CallerFilePathTest.jsx.expected

@@ -0,0 +1,19 @@
+
+import { class_type } from "./fable_modules/fable-library-js/Reflection.js";
+import { printf, toConsole } from "./fable_modules/fable-library-js/String.js";
+
+export class Log {
+    constructor() {
+    }
+}
+
+export function Log_$reflection() {
+    return class_type("CallerFilePathTest.Log", undefined, Log);
+}
+
+export function Log_info_Z384F8060(message, path = "") {
+    toConsole(printf("%s: %s"))(path)(message);
+}
+
+Log_info_Z384F8060("hello", "./CallerFilePathTest.fs");
+

tests/Integration/Integration/data/pathMap/pathMap.fsproj

@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <RollForward>Major</RollForward>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <PathMap>$(MSBuildThisFileDirectory)=.</PathMap>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="CallerFilePathTest.fs" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Fable.Core" Version="4.5.0" />
+  </ItemGroup>
+
+</Project>