From 4d2789c8caba809db00a7322cf4e88eb7ede521b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tom=20Houl=C3=A9?= <tom@tomhoule.com>
Date: Thu, 23 Dec 2021 07:55:38 +0100
Subject: [PATCH] Let prisma_fmt::format() take parameters for tab size

The API is modelled on an LSP formatting request. The
DocumentFormattingParams contain, among other options, the tab size,
which we then pass to the reformatter. Note that this is a breaking API
change, so we'll have to pay attention to prisma-fmt-wasm, and probably
skip a (failed) release there.
---
 prisma-fmt/src/lib.rs                         | 30 ++++++++++++++++---
 .../text_document_completion/test_api.rs      |  2 +-
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/prisma-fmt/src/lib.rs b/prisma-fmt/src/lib.rs
index efc50111497b..558da0c48688 100644
--- a/prisma-fmt/src/lib.rs
+++ b/prisma-fmt/src/lib.rs
@@ -4,14 +4,17 @@ mod native;
 mod preview;
 mod text_document_completion;
 
+use log::*;
+
 /// The API is modelled on an LSP [completion
 /// request](https://github.com/microsoft/language-server-protocol/blob/gh-pages/_specifications/specification-3-16.md#textDocument_completion).
 /// Input and output are both JSON, the request being a `CompletionParams` object and the response
 /// being a `CompletionList` object.
-pub fn text_document_completion(schema: &str, params: String) -> String {
-    let params = if let Ok(params) = serde_json::from_str::<lsp_types::CompletionParams>(&params) {
+pub fn text_document_completion(schema: &str, params: &str) -> String {
+    let params = if let Ok(params) = serde_json::from_str::<lsp_types::CompletionParams>(params) {
         params
     } else {
+        warn!("Failed to parse params to text_document_completion() as CompletionParams.");
         return serde_json::to_string(&text_document_completion::empty_completion_list()).unwrap();
     };
 
@@ -20,9 +23,28 @@ pub fn text_document_completion(schema: &str, params: String) -> String {
     serde_json::to_string(&completion_list).unwrap()
 }
 
-pub fn format(schema: String) -> String {
+/// The two parameters are:
+/// - The Prisma schema to reformat, as a string.
+/// - An LSP
+/// [DocumentFormattingParams](https://github.com/microsoft/language-server-protocol/blob/gh-pages/_specifications/specification-3-16.md#textDocument_formatting) object, as JSON.
+///
+/// The function returns the formatted schema, as a string.
+///
+/// Of the DocumentFormattingParams, we only take into account tabSize, at the moment.
+pub fn format(schema: &str, params: &str) -> String {
     use datamodel::ast::reformat::Reformatter;
-    Reformatter::new(&schema).reformat_to_string()
+
+    let params: lsp_types::DocumentFormattingParams = match serde_json::from_str(params) {
+        Ok(params) => params,
+        Err(err) => {
+            warn!("Error parsing DocumentFormattingParams params: {}", err);
+            return schema.to_owned();
+        }
+    };
+
+    let mut out = Vec::with_capacity(schema.len() / 2);
+    Reformatter::new(schema).reformat_to(&mut out, params.options.tab_size as usize);
+    String::from_utf8_lossy(&out).into_owned()
 }
 
 pub fn lint(schema: String) -> String {
diff --git a/prisma-fmt/tests/text_document_completion/test_api.rs b/prisma-fmt/tests/text_document_completion/test_api.rs
index 3d242b1adf3e..dbd412f687c6 100644
--- a/prisma-fmt/tests/text_document_completion/test_api.rs
+++ b/prisma-fmt/tests/text_document_completion/test_api.rs
@@ -32,7 +32,7 @@ pub(crate) fn test_scenario(scenario_name: &str) {
         context: None,
     };
 
-    let result = prisma_fmt::text_document_completion(&schema, serde_json::to_string_pretty(&params).unwrap());
+    let result = prisma_fmt::text_document_completion(&schema, &serde_json::to_string_pretty(&params).unwrap());
     // Prettify the JSON
     let result =
         serde_json::to_string_pretty(&serde_json::from_str::<lsp_types::CompletionList>(&result).unwrap()).unwrap();