2 files changed, 77 insertions, 0 deletions
diff --git a/test/cepis_test.rb b/test/cepis_test.rb
index 06a6bf6..6fd3353 100644
--- a/test/cepis_test.rb
+++ b/test/cepis_test.rb
@@ -91,6 +91,67 @@ class LookupTest < ServerTest
     assert_includes error.message, "99999999"
   end
 
+  def test_not_found_carries_the_band
+    body = { "erro" => "cep_nao_encontrado", "mensagem" => "CEP não existe na base do DNE",
+             "faixa" => AREAL_FAIXA }
+    routes.respond("/25845000", [404, JSON.generate(body), {}])
+    error = assert_raises(Cepis::CEPNotFound) { @client.lookup("25845000") }
+
+    assert_equal "Areal", error.faixa.localidade
+    assert_equal "RJ", error.faixa.uf
+    assert_equal "3300225", error.faixa.ibge
+    assert_equal 118, error.faixa.ceps
+    # The band starts above the CEP that just failed: cep_ini is the smallest
+    # CEP that exists, not the DNE's published start, which is 25845000.
+    assert_equal "25845001", error.faixa.cep_ini
+    assert_equal "25849899", error.faixa.cep_fim
+  end
+
+  def test_the_band_names_the_municipality_in_the_message
+    body = { "erro" => "cep_nao_encontrado", "faixa" => AREAL_FAIXA }
+    routes.respond("/25845000", [404, JSON.generate(body), {}])
+    error = assert_raises(Cepis::CEPNotFound) { @client.lookup("25845000") }
+
+    assert_includes error.message, "25845000"
+    assert_includes error.message, "Areal/RJ"
+  end
+
+  def test_band_is_absent_when_no_municipality_owns_the_numbers
+    # The API omits `faixa` in that case — it never sends null.
+    routes.respond(
+      "/99999999",
+      [404, JSON.generate({ "erro" => "cep_nao_encontrado", "mensagem" => "gone" }), {}]
+    )
+    error = assert_raises(Cepis::CEPNotFound) { @client.lookup("99999999") }
+
+    assert_nil error.faixa
+  end
+
+  def test_malformed_band_does_not_break_the_not_found
+    ["Areal", {}, { "uf" => "RJ" }, { "localidade" => "" }, [], 7].each do |faixa|
+      body = { "erro" => "cep_nao_encontrado", "faixa" => faixa }
+      routes.respond("/99999999", [404, JSON.generate(body), {}])
+      error = assert_raises(Cepis::CEPNotFound) { @client.lookup("99999999") }
+
+      assert_nil error.faixa, "expected #{faixa.inspect} to be ignored"
+      assert_includes error.message, "99999999"
+    end
+  end
+
+  def test_unreadable_404_body_is_still_a_clean_not_found
+    routes.respond("/99999999", [404, "<html>captive portal</html>", {}])
+    error = assert_raises(Cepis::CEPNotFound) { @client.lookup("99999999") }
+
+    assert_nil error.faixa
+  end
+
+  def test_band_never_turns_a_not_found_into_an_address
+    body = { "erro" => "cep_nao_encontrado", "faixa" => AREAL_FAIXA }
+    routes.respond("/25845000", [404, JSON.generate(body), {}])
+
+    assert_raises(Cepis::CEPNotFound) { @client.lookup("25845000") }
+  end
+
   def test_not_found_is_not_retried
     routes.respond("/99999999", [404, JSON.generate({ "erro" => "x" }), {}])
     assert_raises(Cepis::CEPNotFound) { @client.lookup("99999999") }
diff --git a/test/test_helper.rb b/test/test_helper.rb
index e12bd9d..48b581d 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -24,6 +24,22 @@ SE_ADDRESS = {
   "siafi" => "7107"
 }.freeze
 
+# The band of a CEP that does not exist, as the API returns it on the 404.
+#
+# 25845000 is the DNE's own start for Areal and does not exist: `cep_ini` is
+# the smallest CEP that really is there, one number above it. The 118 CEPs are
+# scattered across the ~4,900 numbers up to `cep_fim`.
+AREAL_FAIXA = {
+  "localidade" => "Areal",
+  "uf" => "RJ",
+  "estado" => "Rio de Janeiro",
+  "regiao" => "Sudeste",
+  "ibge" => "3300225",
+  "cep_ini" => "25845001",
+  "cep_fim" => "25849899",
+  "ceps" => 118
+}.freeze
+
 CSV_HEADER = "cep,logradouro,complemento,unidade,bairro,localidade,uf,estado," \
              "regiao,ibge,gia,ddd,siafi"