From 39609da7af2965682cbea7cde63562affc93ab72 Mon Sep 17 00:00:00 2001
From: Johannes Baiter <johannes.baiter@gmail.com>
Date: Thu, 28 Mar 2019 19:43:06 +0100
Subject: [PATCH] digraphs: Allow input in reverse order (fixes #3599) (#3635)

---
 src/actions/commands/insert.ts | 29 ++++++++++++++++++++++++++---
 test/mode/modeInsert.test.ts   |  9 ++++++---
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/src/actions/commands/insert.ts b/src/actions/commands/insert.ts
index 46b4ed54b03..4e7c89f0c2a 100644
--- a/src/actions/commands/insert.ts
+++ b/src/actions/commands/insert.ts
@@ -306,7 +306,14 @@ class CommandInsertDigraph extends BaseCommand {
 
   public async exec(position: Position, vimState: VimState): Promise<VimState> {
     const digraph = this.keysPressed.slice(1, 3).join('');
-    let charCodes = (DefaultDigraphs[digraph] || configuration.digraphs[digraph])[1];
+    const reverseDigraph = digraph
+      .split('')
+      .reverse()
+      .join('');
+    let charCodes = (DefaultDigraphs[digraph] ||
+      DefaultDigraphs[reverseDigraph] ||
+      configuration.digraphs[digraph] ||
+      configuration.digraphs[reverseDigraph])[1];
     if (!(charCodes instanceof Array)) {
       charCodes = [charCodes];
     }
@@ -324,7 +331,16 @@ class CommandInsertDigraph extends BaseCommand {
       return false;
     }
     const chars = keysPressed.slice(1, 3).join('');
-    return chars in configuration.digraphs || chars in DefaultDigraphs;
+    const reverseChars = chars
+      .split('')
+      .reverse()
+      .join('');
+    return (
+      chars in configuration.digraphs ||
+      reverseChars in configuration.digraphs ||
+      chars in DefaultDigraphs ||
+      reverseChars in DefaultDigraphs
+    );
   }
 
   public couldActionApply(vimState: VimState, keysPressed: string[]): boolean {
@@ -332,8 +348,15 @@ class CommandInsertDigraph extends BaseCommand {
       return false;
     }
     const chars = keysPressed.slice(1, keysPressed.length).join('');
+    const reverseChars = chars
+      .split('')
+      .reverse()
+      .join('');
     if (chars.length > 0) {
-      const predicate = (digraph: string) => chars === digraph.substring(0, chars.length);
+      const predicate = (digraph: string) => {
+        const digraphChars = digraph.substring(0, chars.length);
+        return chars === digraphChars || reverseChars === digraphChars;
+      };
       const match =
         Object.keys(configuration.digraphs).find(predicate) ||
         Object.keys(DefaultDigraphs).find(predicate);
diff --git a/test/mode/modeInsert.test.ts b/test/mode/modeInsert.test.ts
index 5b24bfe5769..bfc51200f0d 100644
--- a/test/mode/modeInsert.test.ts
+++ b/test/mode/modeInsert.test.ts
@@ -347,8 +347,11 @@ suite('Mode Insert', () => {
       'e',
       'x',
       't',
+      '<C-k>',
+      '>',
+      '-',
     ]);
-    assertEqualLines(['text→text']);
+    assertEqualLines(['text→text→']);
   });
 
   test('Can handle custom digraph insert', async () => {
@@ -356,7 +359,7 @@ suite('Mode Insert', () => {
       'R!': ['🚀', [55357, 56960]],
     };
     await reloadConfiguration();
-    await modeHandler.handleMultipleKeyEvents(['i', '<C-k>', 'R', '!']);
-    assertEqualLines(['🚀']);
+    await modeHandler.handleMultipleKeyEvents(['i', '<C-k>', 'R', '!', '<C-k>', '!', 'R']);
+    assertEqualLines(['🚀🚀']);
   });
 });