fix(imports): support QIF dd mmm yyyy date format (#2500)

* Fix QIF import for dd mmm yyyy dates (#2498)

American Express QIF exports use dd mmm yyyy D-fields (e.g. D26 Jan 2026).
Import previously failed with "Unable to detect date format" for two reasons:

1. QifParser.normalize_qif_date stripped all internal whitespace, turning
   26 Jan 2026 into the unparseable 26Jan2026. For month-name dates the
   space IS the separator, so collapse multiples to a single space instead
   of removing them. Numeric dates keep the existing strip-all behavior.

2. Family::DATE_FORMATS had no candidate mapping to dd mmm yyyy, so
   detect_date_format could not match it. Add "%d %b %Y" (DD MMM YYYY).

Extend the 2-digit-year expansion separator class to include space so
month-name dates with 2-digit years also normalize (26 Jan 26 -> 26 Jan 2026).

Covered by normalize/parse/detect and Amex-style row-generation regression
tests in qif_import_test.rb.

* test(qif): cover month-name 2-digit year normalization & parse

Addresses CodeRabbit nitpick on #2500: the production change extends
the 2-digit-year expansion regex separator class to include a space
so month-name dates like "26 Jan 26" normalize to "26 Jan 2026".
Add normalize_qif_date and parse_qif_date regressions for that branch.

app/models/concerns/qif_parser.rb

@@ -354,12 +354,15 @@ module QifParser
   #   - Optional spaces around components:  6/ 4'20  →  6/4/20
   #   - Dot separators:  04.06.2020
   #   - Dash separators:  04-06-2020
+  #   - Month-name separators:  26 Jan 2026  (Amex-style "dd mmm yyyy")
   #
   # This method:
   #   1. Strips whitespace
   #   2. Replaces the Quicken apostrophe with the file's date separator
-  #   3. Expands 2-digit years to 4-digit (00-99 → 2000-2099, capped at current year)
-  #   4. Returns a cleaned date string suitable for Date.strptime
+  #   3. Collapses whitespace (removes it for numeric dates; keeps single
+  #      spaces for month-name dates since the space IS the separator)
+  #   4. Expands 2-digit years to 4-digit (00-99 → 2000-2099, capped at current year)
+  #   5. Returns a cleaned date string suitable for Date.strptime
   def self.normalize_qif_date(date_str)
     return nil if date_str.blank?
 
@@ -371,12 +374,20 @@ module QifParser
       s = s.gsub("'", sep)
     end
 
-    # Remove internal spaces (e.g. "6/ 4/20" → "6/4/20")
-    s = s.gsub(/\s+/, "")
+    # Whitespace handling depends on the date style:
+    #   - Month-name dates (e.g. "26 Jan 2026") use spaces as the field
+    #     separator, so collapse multiples to a single space.
+    #   - Numeric dates (e.g. Quicken's padded "6/ 4/20") use / . or - as
+    #     separators and may carry stray padding spaces, so strip them.
+    if s.match?(/[A-Za-z]/)
+      s = s.gsub(/\s+/, " ").strip
+    else
+      s = s.gsub(/\s+/, "")
+    end
 
     # Expand 2-digit year at end to 4-digit, but only when the string doesn't
     # already contain a 4-digit number (which would be a full year).
-    if !s.match?(/\d{4}/) && (m = s.match(%r{\A(.+[/.\-])(\d{2})\z}))
+    if !s.match?(/\d{4}/) && (m = s.match(%r{\A(.+[/.\- ])(\d{2})\z}))
       short_year = m[2].to_i
       full_year  = 2000 + short_year
       full_year -= 100 if full_year > Date.today.year

app/models/family.rb

@@ -15,7 +15,9 @@ class Family < ApplicationRecord
     [ "MM/DD/YYYY", "%m/%d/%Y" ],
     [ "D/MM/YYYY", "%e/%m/%Y" ],
     [ "YYYY.MM.DD", "%Y.%m.%d" ],
-    [ "YYYYMMDD", "%Y%m%d" ]
+    [ "YYYYMMDD", "%Y%m%d" ],
+    # QIF month-name imports rely on QifParser preserving normalized spaces.
+    [ "DD MMM YYYY", "%d %b %Y" ]
   ].freeze
 
 

test/models/qif_import_test.rb

@@ -854,6 +854,22 @@ class QifImportTest < ActiveSupport::TestCase
 
   # ── QifParser: normalize_qif_date ──────────────────────────────────────────
 
+  test "normalize_qif_date preserves single spaces for month-name dates" do
+    assert_equal "26 Jan 2026", QifParser.send(:normalize_qif_date, "26 Jan 2026")
+  end
+
+  test "normalize_qif_date collapses multiple spaces in month-name dates" do
+    assert_equal "26 Jan 2026", QifParser.send(:normalize_qif_date, "26  Jan  2026")
+  end
+
+  test "normalize_qif_date still strips spaces from numeric dates" do
+    assert_equal "6/4/2020", QifParser.send(:normalize_qif_date, "6/ 4/2020")
+  end
+
+  test "normalize_qif_date expands 2-digit year for month-name dates" do
+    assert_equal "26 Jan 2026", QifParser.send(:normalize_qif_date, "26 Jan 26")
+  end
+
   test "normalize_qif_date converts apostrophe 2-digit year" do
     assert_equal "6/4/2020", QifParser.send(:normalize_qif_date, "6/ 4'20")
   end
@@ -898,6 +914,14 @@ class QifImportTest < ActiveSupport::TestCase
     assert_equal "2020-06-04", QifParser.send(:parse_qif_date, "2020-06-04", date_format: "%Y-%m-%d")
   end
 
+  test "parse_qif_date parses month-name format (DD MMM YYYY)" do
+    assert_equal "2026-01-26", QifParser.send(:parse_qif_date, "26 Jan 2026", date_format: "%d %b %Y")
+  end
+
+  test "parse_qif_date parses month-name format with 2-digit year" do
+    assert_equal "2026-01-26", QifParser.send(:parse_qif_date, "26 Jan 26", date_format: "%d %b %Y")
+  end
+
   test "parse_qif_date returns nil for invalid date" do
     assert_nil QifParser.send(:parse_qif_date, "13/32/2020", date_format: "%m/%d/%Y")
   end
@@ -962,6 +986,11 @@ class QifImportTest < ActiveSupport::TestCase
     assert_equal "%Y-%m-%d", Import.detect_date_format(samples)
   end
 
+  test "detect_date_format identifies month-name DD MMM YYYY format" do
+    samples = [ "26 Jan 2026", "23 Jan 2026", "02 Feb 2026" ]
+    assert_equal "%d %b %Y", Import.detect_date_format(samples)
+  end
+
   test "detect_date_format returns fallback for blank samples" do
     assert_equal "%Y-%m-%d", Import.detect_date_format([])
     assert_equal "%Y-%m-%d", Import.detect_date_format(nil)
@@ -1016,6 +1045,48 @@ class QifImportTest < ActiveSupport::TestCase
     assert_equal "%d/%m/%Y", @import.reload.qif_date_format
   end
 
+  # Reproduces #2498: Amex-style QIF with dd mmm yyyy dates previously failed
+  # with "Unable to detect date format" because normalize_qif_date stripped all
+  # spaces (turning "26 Jan 2026" into the unparseable "26Jan2026").
+  AMEX_DDD_MMM_YYYY_QIF = <<~QIF
+    !Type:CCard
+    D26 Jan 2026
+    N20260126
+    T-25.24
+    PAMAZON.COM.CA           WWW.AMAZON.CO
+    M
+    ^
+    D23 Jan 2026
+    N20260123
+    T-10.49
+    PSKIPTHEDISHES           WINNIPEG (BROAD
+    M
+    ^
+  QIF
+
+  test "generate_rows_from_csv auto-detects DD MMM YYYY format" do
+    @import.update!(raw_file_str: AMEX_DDD_MMM_YYYY_QIF)
+    @import.generate_rows_from_csv
+
+    assert_equal "%d %b %Y", @import.reload.qif_date_format
+    row = @import.rows.find_by(name: "AMAZON.COM.CA           WWW.AMAZON.CO")
+    assert_not_nil row
+    assert_equal "2026-01-26", row.date
+    assert_equal "-25.24",     row.amount
+  end
+
+  test "DD MMM YYYY format appears in valid_date_formats_with_preview for Amex QIF" do
+    @import.update!(raw_file_str: AMEX_DDD_MMM_YYYY_QIF)
+    @import.generate_rows_from_csv
+
+    formats = @import.valid_date_formats_with_preview
+    format_strs = formats.map { |f| f[:format] }
+
+    assert_includes format_strs, "%d %b %Y"
+    dd_mmm = formats.find { |f| f[:format] == "%d %b %Y" }
+    assert_equal "2026-01-26", dd_mmm[:preview]
+  end
+
   # ── QifParser: try_parse_date ───────────────────────────────────────────────
 
   test "try_parse_date returns ISO date for valid format" do