v1.1.1: theme-token diff card with old/new line-number gutter; hunks carry oldStart/newStart/rows

lib/diff.js

@@ -1,4 +1,6 @@
 // Hunk diffs for the DSH diff card ({path, oldText, newText} per hunk, 3 lines of context).
+// Each hunk also carries `oldStart`/`newStart` (1-based file lines of its first row) and `rows`
+// ([op, text] with op '=', '-', '+') so a client can draw a line-number gutter.
 import { lineMap } from './store.js'
 import { splitLines } from './text.js'
 
@@ -7,16 +9,16 @@ export function hunkDiffs(path, before, after, context = 3) {
   const b = splitLines(after).lines
   const map = lineMap(a, b)
   // Walk both sides, emitting ops: '=' common, '-' removed, '+' added.
-  const ops = []
+  const ops = [] // [op, text, oldLine|null, newLine|null]
   let i = 1; let j = 1
   const pairs = [...map.entries()].sort((x, y) => x[0] - y[0])
   for (const [ai, bj] of pairs) {
-    while (i < ai) ops.push(['-', a[i++ - 1]])
-    while (j < bj) ops.push(['+', b[j++ - 1]])
-    ops.push(['=', a[i - 1]]); i++; j++
+    while (i < ai) { ops.push(['-', a[i - 1], i, null]); i++ }
+    while (j < bj) { ops.push(['+', b[j - 1], null, j]); j++ }
+    ops.push(['=', a[i - 1], i, j]); i++; j++
   }
-  while (i <= a.length) ops.push(['-', a[i++ - 1]])
-  while (j <= b.length) ops.push(['+', b[j++ - 1]])
+  while (i <= a.length) { ops.push(['-', a[i - 1], i, null]); i++ }
+  while (j <= b.length) { ops.push(['+', b[j - 1], null, j]); j++ }
   const changed = ops.map((o, k) => (o[0] !== '=' ? k : -1)).filter((k) => k >= 0)
   if (!changed.length) return []
   const spans = []
@@ -27,12 +29,17 @@ export function hunkDiffs(path, before, after, context = 3) {
     else spans.push([s, e])
   }
   return spans.map(([s, e]) => {
-    const oldL = []; const newL = []
+    const oldL = []; const newL = []; const rows = []
+    let oldStart = null; let newStart = null
     for (let k = s; k <= e; k++) {
-      const [op, text] = ops[k]
-      if (op !== '+') oldL.push(text)
-      if (op !== '-') newL.push(text)
+      const [op, text, ol, nl] = ops[k]
+      if (op !== '+') { oldL.push(text); oldStart ??= ol }
+      if (op !== '-') { newL.push(text); newStart ??= nl }
+      rows.push([op, text])
     }
-    return { path, oldText: oldL.length ? oldL.join('\n') : null, newText: newL.join('\n') }
+    // A pure insertion/deletion side has no line of its own: anchor it next to its neighbour.
+    oldStart ??= Math.max(1, (ops.slice(0, s).findLast((o) => o[2] !== null)?.[2] ?? 0) + 1)
+    newStart ??= Math.max(1, (ops.slice(0, s).findLast((o) => o[3] !== null)?.[3] ?? 0) + 1)
+    return { path, oldText: oldL.length ? oldL.join('\n') : null, newText: newL.join('\n'), oldStart, newStart, rows }
   })
 }