From 7d1055b3132cad052bfd54f7f78b1f38182c9395 Mon Sep 17 00:00:00 2001
From: Paul Hummer <paul@eventuallyanyway.com>
Date: Wed, 20 Jul 2022 10:22:47 -0600
Subject: [PATCH] feat: add function snippet syntax

This patch adds real snippet support to function parameter completion.
This means that one could potentially tab through each parameter in the
parameter list and add their associated values.

This patch is hilariously small and direct now that all the refactoring is
done.

Fixes #435
Fixes #431
---
 src/completion.rs   |  9 +++--
 src/server/tests.rs | 93 +++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 95 insertions(+), 7 deletions(-)

diff --git a/src/completion.rs b/src/completion.rs
index aab88cbd..0520e6c2 100644
--- a/src/completion.rs
+++ b/src/completion.rs
@@ -695,15 +695,16 @@ pub fn complete_call_expr(
 
     completion_params
         .into_iter()
-        .map(|(name, typ)| {
+        .enumerate()
+        .map(|(index, (name, typ))| {
             let insert_text = if let Some(trigger) = trigger {
                 if trigger == "(" {
-                    format!("{}: ", name)
+                    format!("{}: ${}", name, index+1)
                 } else {
-                    format!(" {}: ", name)
+                    format!(" {}: ${}", name, index+1)
                 }
             } else {
-                format!("{}: ", name)
+                format!("{}: ${}", name, index+1)
             };
 
             lsp::CompletionItem {
diff --git a/src/server/tests.rs b/src/server/tests.rs
index d7236fcc..cbdbc933 100644
--- a/src/server/tests.rs
+++ b/src/server/tests.rs
@@ -2020,6 +2020,93 @@ ab = 10
     assert_eq!(expected, labels);
 }
 
+/// Function parameter snippets are returned with the snippet syntax
+/// for completion on a a function already written, e.g. from an
+/// automated process.
+#[test]
+async fn test_function_completion_snippet() {
+    let fluxscript = r#"
+from()
+  // ^"#;
+    let server = create_server();
+    open_file(&server, fluxscript.to_string(), None).await;
+
+    let params = lsp::CompletionParams {
+        text_document_position: lsp::TextDocumentPositionParams {
+            text_document: lsp::TextDocumentIdentifier {
+                uri: lsp::Url::parse("file:///home/user/file.flux")
+                    .unwrap(),
+            },
+            position: position_of(&fluxscript),
+        },
+        work_done_progress_params: lsp::WorkDoneProgressParams {
+            work_done_token: None,
+        },
+        partial_result_params: lsp::PartialResultParams {
+            partial_result_token: None,
+        },
+        context: Some(lsp::CompletionContext {
+            trigger_kind: lsp::CompletionTriggerKind::INVOKED,
+            trigger_character: None,
+        }),
+    };
+
+    let result =
+        server.completion(params.clone()).await.unwrap().unwrap();
+
+    let items = match result {
+        lsp::CompletionResponse::List(l) => l.items,
+        _ => unreachable!(),
+    };
+
+    expect![[r#"
+        [
+          {
+            "label": "bucket",
+            "kind": 5,
+            "detail": "string",
+            "insertText": "bucket: $1",
+            "insertTextFormat": 2
+          },
+          {
+            "label": "bucketID",
+            "kind": 5,
+            "detail": "string",
+            "insertText": "bucketID: $2",
+            "insertTextFormat": 2
+          },
+          {
+            "label": "host",
+            "kind": 5,
+            "detail": "string",
+            "insertText": "host: $3",
+            "insertTextFormat": 2
+          },
+          {
+            "label": "org",
+            "kind": 5,
+            "detail": "string",
+            "insertText": "org: $4",
+            "insertTextFormat": 2
+          },
+          {
+            "label": "orgID",
+            "kind": 5,
+            "detail": "string",
+            "insertText": "orgID: $5",
+            "insertTextFormat": 2
+          },
+          {
+            "label": "token",
+            "kind": 5,
+            "detail": "string",
+            "insertText": "token: $6",
+            "insertTextFormat": 2
+          }
+        ]"#]]
+    .assert_eq(&serde_json::to_string_pretty(&items).unwrap());
+}
+
 // XXX: rockstar (6 Jul 2022) - Is this test correct? I think it's not. It's
 // saying that when there's a `now`, and you type `n` it should complete to
 // literally everything? That makes no sense.
@@ -2257,21 +2344,21 @@ csv.from(
               "label": "csv",
               "kind": 5,
               "detail": "string",
-              "insertText": "csv: ",
+              "insertText": "csv: $1",
               "insertTextFormat": 2
             },
             {
               "label": "file",
               "kind": 5,
               "detail": "string",
-              "insertText": "file: ",
+              "insertText": "file: $2",
               "insertTextFormat": 2
             },
             {
               "label": "mode",
               "kind": 5,
               "detail": "string",
-              "insertText": "mode: ",
+              "insertText": "mode: $3",
               "insertTextFormat": 2
             }
           ]