diff --git a/dev/lib/product_taxonomy/models/integration_version.rb b/dev/lib/product_taxonomy/models/integration_version.rb
index 0b84a07f3..d605dc8c1 100644
--- a/dev/lib/product_taxonomy/models/integration_version.rb
+++ b/dev/lib/product_taxonomy/models/integration_version.rb
@@ -30,10 +30,32 @@ def generate_all_distributions(output_path:, logger:, current_shopify_version: n
       #
       # @return [Array<IntegrationVersion>]
       def load_all_from_source(current_shopify_version: nil, base_path: INTEGRATIONS_PATH)
-        integrations = YAML.safe_load_file(File.expand_path("integrations.yml", base_path))
-        integrations.pluck("available_versions").flatten.map do |integration_version|
-          integration_path = File.expand_path(integration_version, base_path)
-          load_from_source(integration_path:, current_shopify_version:)
+        integrations_yaml = YAML.safe_load_file(File.expand_path("integrations.yml", base_path))
+        integrations_yaml.flat_map do |integration_yaml|
+          versions = integration_yaml["available_versions"].sort.map do |version_path|
+            load_from_source(
+              integration_path: File.expand_path(version_path, base_path),
+              current_shopify_version:,
+            )
+          end
+
+          resolve_to_shopify_mappings_chain(versions) if integration_yaml["name"] == "shopify"
+
+          versions
+        end
+      end
+
+      # Resolve a set of IntegrationVersion to_shopify mappings so that each one maps to the latest version of the
+      # Shopify taxonomy.
+      #
+      # @param versions [Array<IntegrationVersion>] The versions to resolve, ordered from oldest to newest.
+      def resolve_to_shopify_mappings_chain(versions)
+        # Resolve newest version against current taxonomy
+        versions.last.resolve_to_shopify_mappings(nil)
+
+        # Resolve each older version against the one following it
+        versions.each_cons(2).reverse_each do |previous, next_version|
+          previous.resolve_to_shopify_mappings(next_version)
         end
       end
 
@@ -155,6 +177,19 @@ def generate_distribution(output_path:, direction:)
       )
     end
 
+    # Resolve the output categories of to_shopify mappings to the next version of the Shopify taxonomy.
+    #
+    # @param next_integration_version [IntegrationVersion | nil] The IntegrationVersion defining mappings to the next
+    #   newer version of the Shopify taxonomy. If nil, the latest version of the Shopify taxonomy is used.
+    def resolve_to_shopify_mappings(next_integration_version)
+      @to_shopify_mappings.each do |mapping|
+        newer_mapping = next_integration_version&.to_shopify_mappings&.find do
+          _1.input_category["id"] == mapping.output_category
+        end
+        mapping.output_category = newer_mapping&.output_category || Category.find_by(id: mapping.output_category)
+      end
+    end
+
     # For a mapping to an external taxonomy, get the IDs of external categories that are not mapped from Shopify.
     #
     # @return [Array<String>] IDs of external categories not mapped from the Shopify taxonomy. Empty if there are no
diff --git a/dev/lib/product_taxonomy/models/mapping_rule.rb b/dev/lib/product_taxonomy/models/mapping_rule.rb
index 9070af167..097789ab2 100644
--- a/dev/lib/product_taxonomy/models/mapping_rule.rb
+++ b/dev/lib/product_taxonomy/models/mapping_rule.rb
@@ -29,7 +29,10 @@ def load_rules_from_source(integration_path:, direction:, full_names_by_id:)
 
           is_to_shopify = direction == :to_shopify
           input_category = is_to_shopify ? full_names_by_id[input_id] : Category.find_by(id: input_id)
-          output_category = is_to_shopify ? Category.find_by(id: output_id) : full_names_by_id[output_id]
+          # We set output_category to be the raw output ID if is_to_shopify is true, with an expectation that it will
+          # be resolved to a `Category` before the rule is serialized to JSON or TXT.
+          # See `IntegrationVersion#resolve_to_shopify_mappings`.
+          output_category = is_to_shopify ? output_id : full_names_by_id[output_id]
 
           raise ArgumentError, "Input category not found for mapping rule: #{rule}" unless input_category
           raise ArgumentError, "Output category not found for mapping rule: #{rule}" unless output_category
@@ -41,7 +44,8 @@ def load_rules_from_source(integration_path:, direction:, full_names_by_id:)
       end
     end
 
-    attr_reader :input_category, :output_category
+    attr_reader :input_category
+    attr_accessor :output_category
 
     def initialize(input_category:, output_category:)
       @input_category = input_category
@@ -87,19 +91,23 @@ def category_json(category)
           id: category["id"].to_s,
           full_name: category["full_name"],
         }
-      else
+      elsif category.is_a?(Category)
         {
           id: category.gid,
           full_name: category.full_name,
         }
+      else
+        raise ArgumentError, "Mapping rule category not resolved. Raw value: #{category}"
       end
     end
 
     def category_txt(category)
       if category.is_a?(Hash)
         category["full_name"]
-      else
+      elsif category.is_a?(Category)
         category.full_name
+      else
+        raise ArgumentError, "Mapping rule category not resolved. Raw value: #{category}"
       end
     end
   end
diff --git a/dev/test/fixtures/data/integrations/foocommerce/1.0.0/full_names.yml b/dev/test/fixtures/data/integrations/foocommerce/1.0.0/full_names.yml
index 7a4990387..9d9e577f5 100644
--- a/dev/test/fixtures/data/integrations/foocommerce/1.0.0/full_names.yml
+++ b/dev/test/fixtures/data/integrations/foocommerce/1.0.0/full_names.yml
@@ -1,5 +1,5 @@
 ---
 - id: 1
-  full_name: Animals & Pet Supplies (foocommerce)
+  full_name: Apparel & Accessories (foocommerce)
 - id: 2
-  full_name: Animals & Pet Supplies > Live Animals (foocommerce)
+  full_name: Apparel & Accessories > Clothing (foocommerce)
diff --git a/dev/test/fixtures/data/integrations/foocommerce/1.0.0/mappings/from_shopify.yml b/dev/test/fixtures/data/integrations/foocommerce/1.0.0/mappings/from_shopify.yml
index 713539a74..59ad2092a 100644
--- a/dev/test/fixtures/data/integrations/foocommerce/1.0.0/mappings/from_shopify.yml
+++ b/dev/test/fixtures/data/integrations/foocommerce/1.0.0/mappings/from_shopify.yml
@@ -1,12 +1,12 @@
 ---
 rules:
 - input:
-    product_category_id: ap
+    product_category_id: aa
   output:
     product_category_id:
     - '1'
 - input:
-    product_category_id: ap-1
+    product_category_id: aa-1
   output:
     product_category_id:
     - '2'
diff --git a/dev/test/fixtures/data/integrations/integrations.yml b/dev/test/fixtures/data/integrations/integrations.yml
index d32a94ae0..e210d6c71 100644
--- a/dev/test/fixtures/data/integrations/integrations.yml
+++ b/dev/test/fixtures/data/integrations/integrations.yml
@@ -5,3 +5,5 @@
 - name: shopify
   available_versions:
     - shopify/2020-01
+    - shopify/2021-01
+    - shopify/2022-01
diff --git a/dev/test/fixtures/data/integrations/shopify/2020-01/full_names.yml b/dev/test/fixtures/data/integrations/shopify/2020-01/full_names.yml
index 4a115fda4..e62ead064 100644
--- a/dev/test/fixtures/data/integrations/shopify/2020-01/full_names.yml
+++ b/dev/test/fixtures/data/integrations/shopify/2020-01/full_names.yml
@@ -1,5 +1,5 @@
 ---
 - id: 1
-  full_name: Animals & Pet Supplies (old shopify)
+  full_name: Apparel & Accessories (2020-01)
 - id: 2
-  full_name: Animals & Pet Supplies > Live Animals (old shopify)
+  full_name: Apparel & Accessories > Clothing (2020-01)
diff --git a/dev/test/fixtures/data/integrations/shopify/2020-01/mappings/to_shopify.yml b/dev/test/fixtures/data/integrations/shopify/2020-01/mappings/to_shopify.yml
index 6bc3ec828..e8eff409d 100644
--- a/dev/test/fixtures/data/integrations/shopify/2020-01/mappings/to_shopify.yml
+++ b/dev/test/fixtures/data/integrations/shopify/2020-01/mappings/to_shopify.yml
@@ -1,12 +1,14 @@
 ---
+input_taxonomy: shopify/2020-01
+output_taxonomy: shopify/2021-01
 rules:
 - input:
     product_category_id: 1
   output:
     product_category_id:
-    - ap
+    - aa
 - input:
     product_category_id: 2
   output:
     product_category_id:
-    - ap-1
+    - aa-1
diff --git a/dev/test/fixtures/data/integrations/shopify/2021-01/full_names.yml b/dev/test/fixtures/data/integrations/shopify/2021-01/full_names.yml
new file mode 100644
index 000000000..de88e16b6
--- /dev/null
+++ b/dev/test/fixtures/data/integrations/shopify/2021-01/full_names.yml
@@ -0,0 +1,3 @@
+---
+- id: aa-1
+  full_name: Apparel & Accessories > Clothing (2021-01)
diff --git a/dev/test/fixtures/data/integrations/shopify/2021-01/mappings/to_shopify.yml b/dev/test/fixtures/data/integrations/shopify/2021-01/mappings/to_shopify.yml
new file mode 100644
index 000000000..0d1d3b4d8
--- /dev/null
+++ b/dev/test/fixtures/data/integrations/shopify/2021-01/mappings/to_shopify.yml
@@ -0,0 +1,9 @@
+---
+input_taxonomy: shopify/2021-01
+output_taxonomy: shopify/2022-01
+rules:
+- input:
+    product_category_id: aa-1
+  output:
+    product_category_id:
+    - aa-2
diff --git a/dev/test/fixtures/data/integrations/shopify/2022-01/full_names.yml b/dev/test/fixtures/data/integrations/shopify/2022-01/full_names.yml
new file mode 100644
index 000000000..018942b19
--- /dev/null
+++ b/dev/test/fixtures/data/integrations/shopify/2022-01/full_names.yml
@@ -0,0 +1,3 @@
+---
+- id: aa-2
+  full_name: Apparel & Accessories > Clothing Accessories (2022-01)
diff --git a/dev/test/fixtures/data/integrations/shopify/2022-01/mappings/to_shopify.yml b/dev/test/fixtures/data/integrations/shopify/2022-01/mappings/to_shopify.yml
new file mode 100644
index 000000000..b92de4daa
--- /dev/null
+++ b/dev/test/fixtures/data/integrations/shopify/2022-01/mappings/to_shopify.yml
@@ -0,0 +1,9 @@
+---
+input_taxonomy: shopify/2022-01
+output_taxonomy: shopify/2025-01-unstable
+rules:
+- input:
+    product_category_id: aa-2
+  output:
+    product_category_id:
+    - aa-3
diff --git a/dev/test/fixtures/dist/en/integrations/all_mappings.json b/dev/test/fixtures/dist/en/integrations/all_mappings.json
new file mode 100644
index 000000000..268b99e66
--- /dev/null
+++ b/dev/test/fixtures/dist/en/integrations/all_mappings.json
@@ -0,0 +1,125 @@
+{
+  "version": "2025-01-unstable",
+  "mappings": [
+    {
+      "input_taxonomy": "shopify/2025-01-unstable",
+      "output_taxonomy": "foocommerce/1.0.0",
+      "rules": [
+        {
+          "input": {
+            "category": {
+              "id": "gid://shopify/TaxonomyCategory/aa",
+              "full_name": "Apparel & Accessories"
+            }
+          },
+          "output": {
+            "category": [
+              {
+                "id": "1",
+                "full_name": "Apparel & Accessories (foocommerce)"
+              }
+            ]
+          }
+        },
+        {
+          "input": {
+            "category": {
+              "id": "gid://shopify/TaxonomyCategory/aa-1",
+              "full_name": "Apparel & Accessories > Clothing"
+            }
+          },
+          "output": {
+            "category": [
+              {
+                "id": "2",
+                "full_name": "Apparel & Accessories > Clothing (foocommerce)"
+              }
+            ]
+          }
+        }
+      ]
+    },
+    {
+      "input_taxonomy": "shopify/2020-01",
+      "output_taxonomy": "shopify/2025-01-unstable",
+      "rules": [
+        {
+          "input": {
+            "category": {
+              "id": "1",
+              "full_name": "Apparel & Accessories (2020-01)"
+            }
+          },
+          "output": {
+            "category": [
+              {
+                "id": "gid://shopify/TaxonomyCategory/aa",
+                "full_name": "Apparel & Accessories"
+              }
+            ]
+          }
+        },
+        {
+          "input": {
+            "category": {
+              "id": "2",
+              "full_name": "Apparel & Accessories > Clothing (2020-01)"
+            }
+          },
+          "output": {
+            "category": [
+              {
+                "id": "gid://shopify/TaxonomyCategory/aa-3",
+                "full_name": "Apparel & Accessories > Costumes & Accessories"
+              }
+            ]
+          }
+        }
+      ]
+    },
+    {
+      "input_taxonomy": "shopify/2021-01",
+      "output_taxonomy": "shopify/2025-01-unstable",
+      "rules": [
+        {
+          "input": {
+            "category": {
+              "id": "aa-1",
+              "full_name": "Apparel & Accessories > Clothing (2021-01)"
+            }
+          },
+          "output": {
+            "category": [
+              {
+                "id": "gid://shopify/TaxonomyCategory/aa-3",
+                "full_name": "Apparel & Accessories > Costumes & Accessories"
+              }
+            ]
+          }
+        }
+      ]
+    },
+    {
+      "input_taxonomy": "shopify/2022-01",
+      "output_taxonomy": "shopify/2025-01-unstable",
+      "rules": [
+        {
+          "input": {
+            "category": {
+              "id": "aa-2",
+              "full_name": "Apparel & Accessories > Clothing Accessories (2022-01)"
+            }
+          },
+          "output": {
+            "category": [
+              {
+                "id": "gid://shopify/TaxonomyCategory/aa-3",
+                "full_name": "Apparel & Accessories > Costumes & Accessories"
+              }
+            ]
+          }
+        }
+      ]
+    }
+  ]
+}
diff --git a/dev/test/fixtures/dist/en/integrations/foocommerce/shopify_2025-01_to_foocommerce_1.0.0.json b/dev/test/fixtures/dist/en/integrations/foocommerce/shopify_2025-01_to_foocommerce_1.0.0.json
new file mode 100644
index 000000000..96c6626f5
--- /dev/null
+++ b/dev/test/fixtures/dist/en/integrations/foocommerce/shopify_2025-01_to_foocommerce_1.0.0.json
@@ -0,0 +1,43 @@
+{
+  "version": "2025-01-unstable",
+  "mappings": [
+    {
+      "input_taxonomy": "shopify/2025-01-unstable",
+      "output_taxonomy": "foocommerce/1.0.0",
+      "rules": [
+        {
+          "input": {
+            "category": {
+              "id": "gid://shopify/TaxonomyCategory/aa",
+              "full_name": "Apparel & Accessories"
+            }
+          },
+          "output": {
+            "category": [
+              {
+                "id": "1",
+                "full_name": "Apparel & Accessories (foocommerce)"
+              }
+            ]
+          }
+        },
+        {
+          "input": {
+            "category": {
+              "id": "gid://shopify/TaxonomyCategory/aa-1",
+              "full_name": "Apparel & Accessories > Clothing"
+            }
+          },
+          "output": {
+            "category": [
+              {
+                "id": "2",
+                "full_name": "Apparel & Accessories > Clothing (foocommerce)"
+              }
+            ]
+          }
+        }
+      ]
+    }
+  ]
+}
diff --git a/dev/test/fixtures/dist/en/integrations/foocommerce/shopify_2025-01_to_foocommerce_1.0.0.txt b/dev/test/fixtures/dist/en/integrations/foocommerce/shopify_2025-01_to_foocommerce_1.0.0.txt
new file mode 100644
index 000000000..d8229d87e
--- /dev/null
+++ b/dev/test/fixtures/dist/en/integrations/foocommerce/shopify_2025-01_to_foocommerce_1.0.0.txt
@@ -0,0 +1,10 @@
+# Shopify Product Taxonomy - Mapping shopify/2025-01-unstable to foocommerce/1.0.0
+# Format:
+# → {base taxonomy category name}
+# ⇒ {mapped taxonomy category name}
+
+→ Apparel & Accessories
+⇒ Apparel & Accessories (foocommerce)
+
+→ Apparel & Accessories > Clothing
+⇒ Apparel & Accessories > Clothing (foocommerce)
diff --git a/dev/test/fixtures/dist/en/integrations/shopify/shopify_2020-01_to_shopify_2025-01.json b/dev/test/fixtures/dist/en/integrations/shopify/shopify_2020-01_to_shopify_2025-01.json
new file mode 100644
index 000000000..b1dc31d87
--- /dev/null
+++ b/dev/test/fixtures/dist/en/integrations/shopify/shopify_2020-01_to_shopify_2025-01.json
@@ -0,0 +1,43 @@
+{
+  "version": "2025-01-unstable",
+  "mappings": [
+    {
+      "input_taxonomy": "shopify/2020-01",
+      "output_taxonomy": "shopify/2025-01-unstable",
+      "rules": [
+        {
+          "input": {
+            "category": {
+              "id": "1",
+              "full_name": "Apparel & Accessories (2020-01)"
+            }
+          },
+          "output": {
+            "category": [
+              {
+                "id": "gid://shopify/TaxonomyCategory/aa",
+                "full_name": "Apparel & Accessories"
+              }
+            ]
+          }
+        },
+        {
+          "input": {
+            "category": {
+              "id": "2",
+              "full_name": "Apparel & Accessories > Clothing (2020-01)"
+            }
+          },
+          "output": {
+            "category": [
+              {
+                "id": "gid://shopify/TaxonomyCategory/aa-3",
+                "full_name": "Apparel & Accessories > Costumes & Accessories"
+              }
+            ]
+          }
+        }
+      ]
+    }
+  ]
+}
diff --git a/dev/test/fixtures/dist/en/integrations/shopify/shopify_2020-01_to_shopify_2025-01.txt b/dev/test/fixtures/dist/en/integrations/shopify/shopify_2020-01_to_shopify_2025-01.txt
new file mode 100644
index 000000000..8608efa36
--- /dev/null
+++ b/dev/test/fixtures/dist/en/integrations/shopify/shopify_2020-01_to_shopify_2025-01.txt
@@ -0,0 +1,10 @@
+# Shopify Product Taxonomy - Mapping shopify/2020-01 to shopify/2025-01-unstable
+# Format:
+# → {base taxonomy category name}
+# ⇒ {mapped taxonomy category name}
+
+→ Apparel & Accessories (2020-01)
+⇒ Apparel & Accessories
+
+→ Apparel & Accessories > Clothing (2020-01)
+⇒ Apparel & Accessories > Costumes & Accessories
diff --git a/dev/test/fixtures/dist/en/integrations/shopify/shopify_2021-01_to_shopify_2025-01.json b/dev/test/fixtures/dist/en/integrations/shopify/shopify_2021-01_to_shopify_2025-01.json
new file mode 100644
index 000000000..1e8c9b8ec
--- /dev/null
+++ b/dev/test/fixtures/dist/en/integrations/shopify/shopify_2021-01_to_shopify_2025-01.json
@@ -0,0 +1,27 @@
+{
+  "version": "2025-01-unstable",
+  "mappings": [
+    {
+      "input_taxonomy": "shopify/2021-01",
+      "output_taxonomy": "shopify/2025-01-unstable",
+      "rules": [
+        {
+          "input": {
+            "category": {
+              "id": "aa-1",
+              "full_name": "Apparel & Accessories > Clothing (2021-01)"
+            }
+          },
+          "output": {
+            "category": [
+              {
+                "id": "gid://shopify/TaxonomyCategory/aa-3",
+                "full_name": "Apparel & Accessories > Costumes & Accessories"
+              }
+            ]
+          }
+        }
+      ]
+    }
+  ]
+}
diff --git a/dev/test/fixtures/dist/en/integrations/shopify/shopify_2021-01_to_shopify_2025-01.txt b/dev/test/fixtures/dist/en/integrations/shopify/shopify_2021-01_to_shopify_2025-01.txt
new file mode 100644
index 000000000..70e35bd78
--- /dev/null
+++ b/dev/test/fixtures/dist/en/integrations/shopify/shopify_2021-01_to_shopify_2025-01.txt
@@ -0,0 +1,7 @@
+# Shopify Product Taxonomy - Mapping shopify/2021-01 to shopify/2025-01-unstable
+# Format:
+# → {base taxonomy category name}
+# ⇒ {mapped taxonomy category name}
+
+→ Apparel & Accessories > Clothing (2021-01)
+⇒ Apparel & Accessories > Costumes & Accessories
diff --git a/dev/test/fixtures/dist/en/integrations/shopify/shopify_2022-01_to_shopify_2025-01.json b/dev/test/fixtures/dist/en/integrations/shopify/shopify_2022-01_to_shopify_2025-01.json
new file mode 100644
index 000000000..dc69df44f
--- /dev/null
+++ b/dev/test/fixtures/dist/en/integrations/shopify/shopify_2022-01_to_shopify_2025-01.json
@@ -0,0 +1,27 @@
+{
+  "version": "2025-01-unstable",
+  "mappings": [
+    {
+      "input_taxonomy": "shopify/2022-01",
+      "output_taxonomy": "shopify/2025-01-unstable",
+      "rules": [
+        {
+          "input": {
+            "category": {
+              "id": "aa-2",
+              "full_name": "Apparel & Accessories > Clothing Accessories (2022-01)"
+            }
+          },
+          "output": {
+            "category": [
+              {
+                "id": "gid://shopify/TaxonomyCategory/aa-3",
+                "full_name": "Apparel & Accessories > Costumes & Accessories"
+              }
+            ]
+          }
+        }
+      ]
+    }
+  ]
+}
diff --git a/dev/test/fixtures/dist/en/integrations/shopify/shopify_2022-01_to_shopify_2025-01.txt b/dev/test/fixtures/dist/en/integrations/shopify/shopify_2022-01_to_shopify_2025-01.txt
new file mode 100644
index 000000000..dada09750
--- /dev/null
+++ b/dev/test/fixtures/dist/en/integrations/shopify/shopify_2022-01_to_shopify_2025-01.txt
@@ -0,0 +1,7 @@
+# Shopify Product Taxonomy - Mapping shopify/2022-01 to shopify/2025-01-unstable
+# Format:
+# → {base taxonomy category name}
+# ⇒ {mapped taxonomy category name}
+
+→ Apparel & Accessories > Clothing Accessories (2022-01)
+⇒ Apparel & Accessories > Costumes & Accessories
diff --git a/dev/test/integration/generate_mappings_dist_test.rb b/dev/test/integration/generate_mappings_dist_test.rb
new file mode 100644
index 000000000..34041501a
--- /dev/null
+++ b/dev/test/integration/generate_mappings_dist_test.rb
@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+require_relative "../test_helper"
+require "tmpdir"
+
+module ProductTaxonomy
+  class GenerateMappingsDistTest < ActiveSupport::TestCase
+    FIXTURES_PATH = File.expand_path("../fixtures", __dir__)
+
+    setup do
+      @tmp_path = Dir.mktmpdir
+      @current_shopify_version = "2025-01-unstable"
+
+      # Create categories so they can be resolved
+      aa = Category.new(id: "aa", name: "Apparel & Accessories")
+      aa_1 = Category.new(id: "aa-1", name: "Clothing")
+      aa_2 = Category.new(id: "aa-2", name: "Clothing Accessories")
+      aa_3 = Category.new(id: "aa-3", name: "Costumes & Accessories")
+      aa.add_child(aa_1)
+      aa.add_child(aa_2)
+      aa.add_child(aa_3)
+      Category.add(aa)
+      Category.add(aa_1)
+      Category.add(aa_2)
+      Category.add(aa_3)
+    end
+
+    teardown do
+      FileUtils.remove_entry(@tmp_path)
+    end
+
+    test "generate_all_distributions generates all_mappings.json and distribution files for all integration versions" do
+      IntegrationVersion.generate_all_distributions(
+        output_path: @tmp_path,
+        current_shopify_version: @current_shopify_version,
+        logger: stub("logger", info: nil),
+        base_path: File.expand_path("data/integrations", FIXTURES_PATH),
+      )
+
+      assert_file_contents_match "all_mappings.json"
+      assert_file_contents_match "shopify/shopify_2020-01_to_shopify_2025-01.json"
+      assert_file_contents_match "shopify/shopify_2020-01_to_shopify_2025-01.txt"
+      assert_file_contents_match "shopify/shopify_2021-01_to_shopify_2025-01.json"
+      assert_file_contents_match "shopify/shopify_2021-01_to_shopify_2025-01.txt"
+      assert_file_contents_match "shopify/shopify_2022-01_to_shopify_2025-01.json"
+      assert_file_contents_match "shopify/shopify_2022-01_to_shopify_2025-01.txt"
+      assert_file_contents_match "foocommerce/shopify_2025-01_to_foocommerce_1.0.0.json"
+      assert_file_contents_match "foocommerce/shopify_2025-01_to_foocommerce_1.0.0.txt"
+    end
+
+    def assert_file_contents_match(file_path)
+      fixture_path = File.expand_path("dist/en/integrations/#{file_path}", FIXTURES_PATH)
+      expected_path = File.expand_path("en/integrations/#{file_path}", @tmp_path)
+
+      assert(File.exist?(expected_path), "Expected file to exist: #{expected_path}")
+      assert_equal(File.read(fixture_path), File.read(expected_path), "File contents don't match for: #{file_path}")
+    end
+  end
+end
diff --git a/dev/test/models/integration_version_test.rb b/dev/test/models/integration_version_test.rb
index ba5383f8f..4eead9d4f 100644
--- a/dev/test/models/integration_version_test.rb
+++ b/dev/test/models/integration_version_test.rb
@@ -7,16 +7,23 @@ class IntegrationVersionTest < TestCase
     DATA_PATH = File.expand_path("../fixtures/data", __dir__)
 
     setup do
-      ap = Category.new(id: "ap", name: "Animals & Pet Supplies")
-      ap_1 = Category.new(id: "ap-1", name: "Live Animals")
-      ap.add_child(ap_1)
-      Category.add(ap)
-      Category.add(ap_1)
+      aa = Category.new(id: "aa", name: "Apparel & Accessories")
+      aa_1 = Category.new(id: "aa-1", name: "Clothing")
+      aa_2 = Category.new(id: "aa-2", name: "Clothing Accessories")
+      aa_3 = Category.new(id: "aa-3", name: "Costumes & Accessories")
+      aa.add_child(aa_1)
+      aa.add_child(aa_2)
+      aa.add_child(aa_3)
+      Category.add(aa)
+      Category.add(aa_1)
+      Category.add(aa_2)
+      Category.add(aa_3)
       @current_shopify_version = "2025-01-unstable"
       @shopify_integration = IntegrationVersion.load_from_source(
         integration_path: File.expand_path("integrations/shopify/2020-01", DATA_PATH),
         current_shopify_version: @current_shopify_version,
       )
+      @shopify_integration.resolve_to_shopify_mappings(nil) # Resolve against current version
       @external_integration = IntegrationVersion.load_from_source(
         integration_path: File.expand_path("integrations/foocommerce/1.0.0", DATA_PATH),
         current_shopify_version: @current_shopify_version,
@@ -35,11 +42,33 @@ class IntegrationVersionTest < TestCase
         current_shopify_version: @current_shopify_version,
       )
 
-      assert_equal 2, integration_versions.size
+      assert_equal 4, integration_versions.size
       assert_equal "foocommerce", integration_versions.first.name
       assert_equal "1.0.0", integration_versions.first.version
-      assert_equal "shopify", integration_versions.last.name
-      assert_equal "2020-01", integration_versions.last.version
+      assert_equal "shopify", integration_versions.second.name
+      assert_equal "2020-01", integration_versions.second.version
+      assert_equal "shopify", integration_versions.third.name
+      assert_equal "2021-01", integration_versions.third.version
+      assert_equal "shopify", integration_versions.fourth.name
+      assert_equal "2022-01", integration_versions.fourth.version
+    end
+
+    test "load_all_from_source resolves chain of to_shopify mappings against latest version" do
+      integrations_path = File.expand_path("integrations", DATA_PATH)
+      integration_versions = IntegrationVersion.load_all_from_source(
+        base_path: integrations_path,
+        current_shopify_version: @current_shopify_version,
+      )
+      output_mappings = integration_versions
+        .index_by { "#{_1.name}/#{_1.version}" }
+        .transform_values(&:to_shopify_mappings)
+
+      assert_equal "gid://shopify/TaxonomyCategory/aa", output_mappings["shopify/2020-01"].first.output_category.gid
+      # Defined as mapping to aa-1 in the 2020-01 version, resolved through to aa-3
+      assert_equal "gid://shopify/TaxonomyCategory/aa-3", output_mappings["shopify/2020-01"].second.output_category.gid
+      # Defined as mapping to aa-2 in the 2021-01 version, resolved through to aa-3
+      assert_equal "gid://shopify/TaxonomyCategory/aa-3", output_mappings["shopify/2021-01"].first.output_category.gid
+      assert_equal "gid://shopify/TaxonomyCategory/aa-3", output_mappings["shopify/2022-01"].first.output_category.gid
     end
 
     test "to_json returns the JSON representation of a mapping to Shopify" do
@@ -48,25 +77,20 @@ class IntegrationVersionTest < TestCase
         output_taxonomy: "shopify/2025-01-unstable",
         rules: [
           {
-            input: { category: { id: "1", full_name: "Animals & Pet Supplies (old shopify)" } },
+            input: { category: { id: "1", full_name: "Apparel & Accessories (2020-01)" } },
             output: {
               category: [{
-                id: "gid://shopify/TaxonomyCategory/ap",
-                full_name: "Animals & Pet Supplies",
+                id: "gid://shopify/TaxonomyCategory/aa",
+                full_name: "Apparel & Accessories",
               }],
             },
           },
           {
-            input: {
-              category: {
-                id: "2",
-                full_name: "Animals & Pet Supplies > Live Animals (old shopify)",
-              },
-            },
+            input: { category: { id: "2", full_name: "Apparel & Accessories > Clothing (2020-01)" } },
             output: {
               category: [{
-                id: "gid://shopify/TaxonomyCategory/ap-1",
-                full_name: "Animals & Pet Supplies > Live Animals",
+                id: "gid://shopify/TaxonomyCategory/aa-1",
+                full_name: "Apparel & Accessories > Clothing",
               }],
             },
           },
@@ -81,27 +105,22 @@ class IntegrationVersionTest < TestCase
         output_taxonomy: "foocommerce/1.0.0",
         rules: [
           {
-            input: { category: { id: "gid://shopify/TaxonomyCategory/ap", full_name: "Animals & Pet Supplies" } },
+            input: { category: { id: "gid://shopify/TaxonomyCategory/aa", full_name: "Apparel & Accessories" } },
             output: {
               category: [{
                 id: "1",
-                full_name: "Animals & Pet Supplies (foocommerce)",
+                full_name: "Apparel & Accessories (foocommerce)",
               }],
             },
           },
           {
             input: {
               category: {
-                id: "gid://shopify/TaxonomyCategory/ap-1",
-                full_name: "Animals & Pet Supplies > Live Animals",
+                id: "gid://shopify/TaxonomyCategory/aa-1",
+                full_name: "Apparel & Accessories > Clothing",
               },
             },
-            output: {
-              category: [{
-                id: "2",
-                full_name: "Animals & Pet Supplies > Live Animals (foocommerce)",
-              }],
-            },
+            output: { category: [{ id: "2", full_name: "Apparel & Accessories > Clothing (foocommerce)" }] },
           },
         ],
       }
@@ -115,11 +134,11 @@ class IntegrationVersionTest < TestCase
         # → {base taxonomy category name}
         # ⇒ {mapped taxonomy category name}
 
-        → Animals & Pet Supplies (old shopify)
-        ⇒ Animals & Pet Supplies
+        → Apparel & Accessories (2020-01)
+        ⇒ Apparel & Accessories
 
-        → Animals & Pet Supplies > Live Animals (old shopify)
-        ⇒ Animals & Pet Supplies > Live Animals
+        → Apparel & Accessories > Clothing (2020-01)
+        ⇒ Apparel & Accessories > Clothing
       TXT
       assert_equal expected_txt.chomp, @shopify_integration.to_txt(direction: :to_shopify)
     end
@@ -131,11 +150,11 @@ class IntegrationVersionTest < TestCase
         # → {base taxonomy category name}
         # ⇒ {mapped taxonomy category name}
 
-        → Animals & Pet Supplies
-        ⇒ Animals & Pet Supplies (foocommerce)
+        → Apparel & Accessories
+        ⇒ Apparel & Accessories (foocommerce)
 
-        → Animals & Pet Supplies > Live Animals
-        ⇒ Animals & Pet Supplies > Live Animals (foocommerce)
+        → Apparel & Accessories > Clothing
+        ⇒ Apparel & Accessories > Clothing (foocommerce)
       TXT
       assert_equal expected_txt.chomp, @external_integration.to_txt(direction: :from_shopify)
     end
@@ -148,16 +167,19 @@ class IntegrationVersionTest < TestCase
       }
       File.expects(:write).with(
         "/tmp/fake/en/integrations/shopify/shopify_2020-01_to_shopify_2025-01.json",
-        JSON.pretty_generate(expected_shopify_json),
+        JSON.pretty_generate(expected_shopify_json) + "\n",
       )
       File.expects(:write).with(
         "/tmp/fake/en/integrations/shopify/shopify_2020-01_to_shopify_2025-01.txt",
-        @shopify_integration.to_txt(direction: :to_shopify),
-      )
-      @shopify_integration.generate_distribution(
-        output_path: "/tmp/fake",
-        direction: :to_shopify,
+        @shopify_integration.to_txt(direction: :to_shopify) + "\n",
       )
+
+      assert_nothing_raised do
+        @shopify_integration.generate_distribution(
+          output_path: "/tmp/fake",
+          direction: :to_shopify,
+        )
+      end
     end
 
     test "generate_distribution generates the distribution files for a mapping from Shopify" do
@@ -168,16 +190,19 @@ class IntegrationVersionTest < TestCase
       }
       File.expects(:write).with(
         "/tmp/fake/en/integrations/foocommerce/shopify_2025-01_to_foocommerce_1.0.0.json",
-        JSON.pretty_generate(expected_external_json),
+        JSON.pretty_generate(expected_external_json) + "\n",
       )
       File.expects(:write).with(
         "/tmp/fake/en/integrations/foocommerce/shopify_2025-01_to_foocommerce_1.0.0.txt",
-        @external_integration.to_txt(direction: :from_shopify),
-      )
-      @external_integration.generate_distribution(
-        output_path: "/tmp/fake",
-        direction: :from_shopify,
+        @external_integration.to_txt(direction: :from_shopify) + "\n",
       )
+
+      assert_nothing_raised do
+        @external_integration.generate_distribution(
+          output_path: "/tmp/fake",
+          direction: :from_shopify,
+        )
+      end
     end
 
     test "generate_distributions only calls generate_distribution with to_shopify for Shopify integration version" do
@@ -209,52 +234,6 @@ class IntegrationVersionTest < TestCase
       assert_equal expected_json, IntegrationVersion.to_json(mappings:, current_shopify_version: "2025-01-unstable")
     end
 
-    test "generate_all_distributions generates all_mappings.json and distribution files for all integration versions" do
-      FileUtils.expects(:mkdir_p).with("/tmp/fake/en/integrations/foocommerce")
-      FileUtils.expects(:mkdir_p).with("/tmp/fake/en/integrations/shopify")
-      expected_external_json = IntegrationVersion.to_json(
-        mappings: [@external_integration.to_json(direction: :from_shopify)],
-        current_shopify_version: @current_shopify_version,
-      )
-      File.expects(:write).with(
-        "/tmp/fake/en/integrations/foocommerce/shopify_2025-01_to_foocommerce_1.0.0.json",
-        JSON.pretty_generate(expected_external_json),
-      )
-      File.expects(:write).with(
-        "/tmp/fake/en/integrations/foocommerce/shopify_2025-01_to_foocommerce_1.0.0.txt",
-        @external_integration.to_txt(direction: :from_shopify),
-      )
-      expected_shopify_json = IntegrationVersion.to_json(
-        mappings: [@shopify_integration.to_json(direction: :to_shopify)],
-        current_shopify_version: @current_shopify_version,
-      )
-      File.expects(:write).with(
-        "/tmp/fake/en/integrations/shopify/shopify_2020-01_to_shopify_2025-01.json",
-        JSON.pretty_generate(expected_shopify_json),
-      )
-      File.expects(:write).with(
-        "/tmp/fake/en/integrations/shopify/shopify_2020-01_to_shopify_2025-01.txt",
-        @shopify_integration.to_txt(direction: :to_shopify),
-      )
-      all_mappings_json = IntegrationVersion.to_json(
-        mappings: [
-          @external_integration.to_json(direction: :from_shopify),
-          @shopify_integration.to_json(direction: :to_shopify),
-        ],
-        current_shopify_version: @current_shopify_version,
-      )
-      File.expects(:write).with(
-        "/tmp/fake/en/integrations/all_mappings.json",
-        JSON.pretty_generate(all_mappings_json),
-      )
-      IntegrationVersion.generate_all_distributions(
-        output_path: "/tmp/fake",
-        current_shopify_version: @current_shopify_version,
-        logger: stub("logger", info: nil),
-        base_path: File.expand_path("integrations", DATA_PATH),
-      )
-    end
-
     test "unmapped_external_category_ids returns IDs of external categories not mapped from the Shopify taxonomy" do
       external_category1 = { "id" => "1", "full_name" => "External category 1" }
       from_shopify_mappings = [
diff --git a/dev/test/models/mapping_rule_test.rb b/dev/test/models/mapping_rule_test.rb
index 52450db22..3f1825539 100644
--- a/dev/test/models/mapping_rule_test.rb
+++ b/dev/test/models/mapping_rule_test.rb
@@ -112,12 +112,12 @@ class MappingRuleTest < TestCase
       end
     end
 
-    test "load_rules_from_source raises an error if the output category is not found" do
+    test "load_rules_from_source raises an error if the output category is missing" do
       File.expects(:exist?).with("/fake/data/integrations/google/2021-09-21/mappings/to_shopify.yml").returns(true)
       YAML.expects(:safe_load_file)
         .with("/fake/data/integrations/google/2021-09-21/mappings/to_shopify.yml")
         .returns("rules" => [
-          { "input" => { "product_category_id" => "166" }, "output" => { "product_category_id" => ["bb"] } },
+          { "input" => { "product_category_id" => "166" }, "output" => { "product_category_id" => [] } },
         ])
 
       assert_raises(ArgumentError) do
@@ -267,5 +267,25 @@ class MappingRuleTest < TestCase
       )
       refute rule.input_txt_equals_output_txt?
     end
+
+    test "to_txt raises an error if the output category is not resolved" do
+      rule = MappingRule.new(
+        input_category: @shopify_category,
+        output_category: "aa",
+      )
+      assert_raises(ArgumentError) do
+        rule.to_txt
+      end
+    end
+
+    test "to_json raises an error if the output category is not resolved" do
+      rule = MappingRule.new(
+        input_category: @shopify_category,
+        output_category: "aa",
+      )
+      assert_raises(ArgumentError) do
+        rule.to_json
+      end
+    end
   end
 end