feat(transport-ui): import Map step + per-line diff view (M8 E2)

2026-06-18 07:21:23 -04:00
parent e67587ec93
commit c8211f6363
5 changed files with 733 additions and 4 deletions
@@ -0,0 +1,133 @@
+@using System.Text.Json
+
+@*
+   LineDiffView (Component #24, Task M8 E2).
+
+   Renders a single Code field's "lineDiff" payload — the line-level diff that the
+   importer attaches to a Modified ImportPreviewItem's FieldDiffJson for code fields —
+   as a compact, GitHub-style +/- list. Pure presentation: it takes an already-parsed
+   JsonElement (the value of the "lineDiff" key) and walks its "hunks" array.
+
+   hunk op ∈ "context" | "add" | "remove" (lowercase):
+     context → muted line, both old/new line numbers
+     add     → green-ish line, new line number only (no oldLineNo)
+     remove  → red-ish line, old line number only (no newLineNo)
+
+   When the payload's "truncated" flag is true a trailing marker summarises the
+   addedCount / removedCount the diff could not show in full.
+
+   No third-party diff/charting library — Bootstrap utility classes + a small
+   monospace block only.
+*@
+
+@if (_hunks.Count == 0 && !_truncated)
+{
+    <div class="text-muted small fst-italic" data-testid="line-diff-empty">No line-level changes.</div>
+}
+else
+{
+    <div class="border rounded bg-body-tertiary font-monospace small overflow-auto"
+         style="max-height: 22rem;" data-testid="line-diff">
+        @foreach (var hunk in _hunks)
+        {
+            var (rowCls, gutter, sign) = hunk.Op switch
+            {
+                "add" => ("bg-success-subtle text-success-emphasis", FormatGutter(null, hunk.NewLineNo), "+"),
+                "remove" => ("bg-danger-subtle text-danger-emphasis", FormatGutter(hunk.OldLineNo, null), "-"),
+                _ => ("text-body-secondary", FormatGutter(hunk.OldLineNo, hunk.NewLineNo), " "),
+            };
+            <div class="d-flex @rowCls" data-testid="@($"line-diff-{hunk.Op}")">
+                <span class="px-2 text-body-tertiary text-nowrap user-select-none"
+                      style="min-width: 6.5rem;">@gutter</span>
+                <span class="px-1 text-nowrap user-select-none">@sign</span>
+                <span class="px-2 text-break flex-grow-1" style="white-space: pre-wrap;">@hunk.Text</span>
+            </div>
+        }
+    </div>
+
+    @if (_truncated)
+    {
+        <div class="text-muted small fst-italic mt-1" data-testid="line-diff-truncated">
+            … diff truncated (+@_addedCount / -@_removedCount more)
+        </div>
+    }
+}
+
+@code {
+    /// <summary>
+    /// The parsed value of a Modified item's <c>FieldDiffJson</c> code field's
+    /// <c>lineDiff</c> key. When null the component renders nothing meaningful —
+    /// callers should only render it for code fields that actually carry a
+    /// <c>lineDiff</c> object.
+    /// </summary>
+    [Parameter]
+    public JsonElement? LineDiff { get; set; }
+
+    private readonly List<Hunk> _hunks = new();
+    private bool _truncated;
+    private int _addedCount;
+    private int _removedCount;
+
+    private sealed record Hunk(string Op, string Text, int? OldLineNo, int? NewLineNo);
+
+    protected override void OnParametersSet()
+    {
+        _hunks.Clear();
+        _truncated = false;
+        _addedCount = 0;
+        _removedCount = 0;
+
+        if (LineDiff is not { ValueKind: JsonValueKind.Object } payload)
+        {
+            return;
+        }
+
+        if (payload.TryGetProperty("truncated", out var truncatedEl)
+            && truncatedEl.ValueKind is JsonValueKind.True or JsonValueKind.False)
+        {
+            _truncated = truncatedEl.GetBoolean();
+        }
+        if (payload.TryGetProperty("addedCount", out var addedEl)
+            && addedEl.ValueKind == JsonValueKind.Number)
+        {
+            _addedCount = addedEl.GetInt32();
+        }
+        if (payload.TryGetProperty("removedCount", out var removedEl)
+            && removedEl.ValueKind == JsonValueKind.Number)
+        {
+            _removedCount = removedEl.GetInt32();
+        }
+
+        if (payload.TryGetProperty("hunks", out var hunksEl)
+            && hunksEl.ValueKind == JsonValueKind.Array)
+        {
+            foreach (var h in hunksEl.EnumerateArray())
+            {
+                if (h.ValueKind != JsonValueKind.Object)
+                {
+                    continue;
+                }
+                var op = h.TryGetProperty("op", out var opEl) && opEl.ValueKind == JsonValueKind.String
+                    ? opEl.GetString() ?? "context"
+                    : "context";
+                var text = h.TryGetProperty("text", out var textEl) && textEl.ValueKind == JsonValueKind.String
+                    ? textEl.GetString() ?? string.Empty
+                    : string.Empty;
+                int? oldLineNo = h.TryGetProperty("oldLineNo", out var oldEl) && oldEl.ValueKind == JsonValueKind.Number
+                    ? oldEl.GetInt32()
+                    : null;
+                int? newLineNo = h.TryGetProperty("newLineNo", out var newEl) && newEl.ValueKind == JsonValueKind.Number
+                    ? newEl.GetInt32()
+                    : null;
+                _hunks.Add(new Hunk(op, text, oldLineNo, newLineNo));
+            }
+        }
+    }
+
+    private static string FormatGutter(int? oldLineNo, int? newLineNo)
+    {
+        var left = oldLineNo?.ToString() ?? string.Empty;
+        var right = newLineNo?.ToString() ?? string.Empty;
+        return $"{left,3} {right,3}";
+    }
+}