From 4b0123a736fa23de7c7c3b591de5fcf6fab1bf63 Mon Sep 17 00:00:00 2001
From: Jan-Erik Rediger <jrediger@mozilla.com>
Date: Wed, 13 Dec 2023 13:57:47 +0100
Subject: [PATCH] Properly dedent doc strings after parsing in the proc-macro

Fixes #1884
---
 Cargo.lock                                                | 1 +
 fixtures/docstring-proc-macro/src/lib.rs                  | 3 +++
 .../docstring-proc-macro/tests/bindings/test_docstring.py | 8 +++++++-
 fixtures/docstring/src/docstring.udl                      | 3 +++
 fixtures/docstring/tests/bindings/test_docstring.py       | 8 +++++++-
 uniffi_macros/Cargo.toml                                  | 1 +
 uniffi_macros/src/util.rs                                 | 4 ++--
 7 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 6c73b85452..2800a44444 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1872,6 +1872,7 @@ dependencies = [
  "quote",
  "serde",
  "syn",
+ "textwrap",
  "toml",
  "uniffi_build",
  "uniffi_meta",
diff --git a/fixtures/docstring-proc-macro/src/lib.rs b/fixtures/docstring-proc-macro/src/lib.rs
index c8b45abc46..aafe8e5f0c 100644
--- a/fixtures/docstring-proc-macro/src/lib.rs
+++ b/fixtures/docstring-proc-macro/src/lib.rs
@@ -49,6 +49,9 @@ enum AssociatedErrorTest {
 }
 
 /// <docstring-object>
+///
+///   <docstring-object-indented-1>
+///   <docstring-object-indented-2>
 #[derive(uniffi::Object)]
 pub struct ObjectTest {}
 
diff --git a/fixtures/docstring-proc-macro/tests/bindings/test_docstring.py b/fixtures/docstring-proc-macro/tests/bindings/test_docstring.py
index 9c8a1af1c3..7c2385bdbf 100644
--- a/fixtures/docstring-proc-macro/tests/bindings/test_docstring.py
+++ b/fixtures/docstring-proc-macro/tests/bindings/test_docstring.py
@@ -36,7 +36,13 @@
 assert AssociatedErrorTest.Test2.__doc__ == "<docstring-associated-error-variant-2>"
 
 # Test objects
-assert ObjectTest.__doc__ == "<docstring-object>"
+expected_object_doc = """
+    <docstring-object>
+
+      <docstring-object-indented-1>
+      <docstring-object-indented-2>
+    """
+assert ObjectTest.__doc__ == expected_object_doc
 assert ObjectTest.__init__.__doc__ == "<docstring-primary-constructor>"
 assert ObjectTest.new_alternate.__doc__ == "<docstring-alternate-constructor>"
 assert ObjectTest.test.__doc__ == "<docstring-method>"
diff --git a/fixtures/docstring/src/docstring.udl b/fixtures/docstring/src/docstring.udl
index 74963f9121..ffd9de2555 100644
--- a/fixtures/docstring/src/docstring.udl
+++ b/fixtures/docstring/src/docstring.udl
@@ -42,6 +42,9 @@ interface AssociatedErrorTest {
 };
 
 /// <docstring-object>
+///
+///   <docstring-object-indented-1>
+///   <docstring-object-indented-2>
 interface ObjectTest {
     /// <docstring-primary-constructor>
     constructor();
diff --git a/fixtures/docstring/tests/bindings/test_docstring.py b/fixtures/docstring/tests/bindings/test_docstring.py
index 2a029e8a23..d08f8ca057 100644
--- a/fixtures/docstring/tests/bindings/test_docstring.py
+++ b/fixtures/docstring/tests/bindings/test_docstring.py
@@ -36,7 +36,13 @@
 assert AssociatedErrorTest.Test2.__doc__ == "<docstring-associated-error-variant-2>"
 
 # Test objects
-assert ObjectTest.__doc__ == "<docstring-object>"
+expected_object_doc = """
+    <docstring-object>
+
+      <docstring-object-indented-1>
+      <docstring-object-indented-2>
+    """
+assert ObjectTest.__doc__ == expected_object_doc
 assert ObjectTest.__init__.__doc__ == "<docstring-primary-constructor>"
 assert ObjectTest.new_alternate.__doc__ == "<docstring-alternate-constructor>"
 assert ObjectTest.test.__doc__ == "<docstring-method>"
diff --git a/uniffi_macros/Cargo.toml b/uniffi_macros/Cargo.toml
index 79e28300e2..557b05283d 100644
--- a/uniffi_macros/Cargo.toml
+++ b/uniffi_macros/Cargo.toml
@@ -23,6 +23,7 @@ proc-macro2 = "1.0"
 quote = "1.0"
 serde = "1.0.136"
 syn = { version = "2.0", features = ["full", "visit-mut"] }
+textwrap = "0.16.0"
 toml = "0.5.9"
 uniffi_build = { path = "../uniffi_build", version = "=0.25.3" }
 uniffi_meta = { path = "../uniffi_meta", version = "=0.25.3" }
diff --git a/uniffi_macros/src/util.rs b/uniffi_macros/src/util.rs
index d419d80b70..f5d5567f40 100644
--- a/uniffi_macros/src/util.rs
+++ b/uniffi_macros/src/util.rs
@@ -285,11 +285,11 @@ pub(crate) fn extract_docstring(attrs: &[Attribute]) -> syn::Result<String> {
             let name_value = attr.meta.require_name_value()?;
             if let Expr::Lit(expr) = &name_value.value {
                 if let Lit::Str(lit_str) = &expr.lit {
-                    return Ok(lit_str.value().trim().to_owned());
+                    return Ok(lit_str.value());
                 }
             }
             Err(syn::Error::new_spanned(attr, "Cannot parse doc attribute"))
         })
         .collect::<syn::Result<Vec<_>>>()
-        .map(|lines| lines.join("\n"));
+        .map(|lines| textwrap::dedent(&lines.join("\n")));
 }