fix(release): add null-safe fallback for version in createGitTagValues

packages/nx/src/command-line/release/config/config.ts

@@ -920,7 +920,7 @@ export async function createNxReleaseConfig(
       // If any project in the group has docker configuration, disable semver requirement
       releaseGroup.releaseTag.requireSemver = false;
 
-      // Set preferDockerVersion to true by default when docker projects exist,
+      // Set preferDockerVersion by default when docker projects exist,
       // unless user has explicitly configured it
       if (
         releaseGroup.releaseTag.preferDockerVersion === false &&
@@ -931,7 +931,19 @@ export async function createNxReleaseConfig(
         userConfig.releaseTag?.preferDockerVersion === undefined &&
         userConfig.releaseTagPatternPreferDockerVersion === undefined
       ) {
-        releaseGroup.releaseTag.preferDockerVersion = true;
+        // Check if ALL projects have docker config, or just some
+        const allProjectsHaveDocker = releaseGroup.projects.every(
+          (projectName) => {
+            const projectNode = projectGraph.nodes[projectName];
+            const projectDockerConfig = projectNode?.data.release?.docker;
+            return projectDockerConfig !== undefined || !!releaseGroup.docker;
+          }
+        );
+
+        // Use 'both' for mixed groups so non-docker projects fall back correctly
+        releaseGroup.releaseTag.preferDockerVersion = allProjectsHaveDocker
+          ? true
+          : 'both';
       }
     }
   }

packages/nx/src/command-line/release/utils/shared.spec.ts

@@ -636,6 +636,178 @@ describe('shared', () => {
       expect(tags).toEqual(['my-group/a@1.1.0', 'my-group/b@1.2.0']);
     });
 
+    it('should fall back to newVersion when preferDockerVersion is true but dockerVersion is null (fixed group)', () => {
+      const { releaseGroup, releaseGroupToFilteredProjects } =
+        setUpReleaseGroup();
+      releaseGroup.releaseTag.preferDockerVersion = true;
+
+      const tags = createGitTagValues(
+        [releaseGroup],
+        releaseGroupToFilteredProjects,
+        {
+          a: {
+            currentVersion: '1.0.0',
+            dependentProjects: [],
+            newVersion: '1.1.0',
+            dockerVersion: null,
+          },
+          b: {
+            currentVersion: '1.0.0',
+            dependentProjects: [],
+            newVersion: '1.1.0',
+            dockerVersion: null,
+          },
+        }
+      );
+
+      expect(tags).toEqual(['my-group-1.1.0']);
+    });
+
+    it('should fall back to newVersion when preferDockerVersion is true but dockerVersion is null (independent group)', () => {
+      const projects = ['a', 'b'];
+      const releaseGroup: ReleaseGroupWithName = {
+        name: 'my-group',
+        projects,
+        projectsRelationship: 'independent',
+        releaseTag: {
+          pattern: '{projectName}-{version}',
+          checkAllBranchesWhen: undefined,
+          requireSemver: true,
+          preferDockerVersion: true,
+          strictPreid: false,
+        },
+        changelog: undefined,
+        version: undefined,
+        versionPlans: false,
+        resolvedVersionPlans: false,
+      };
+      const releaseGroupToFilteredProjects = new Map().set(
+        releaseGroup,
+        new Set(projects)
+      );
+
+      const tags = createGitTagValues(
+        [releaseGroup],
+        releaseGroupToFilteredProjects,
+        {
+          a: {
+            currentVersion: '1.0.0',
+            dependentProjects: [],
+            newVersion: '1.1.0',
+            dockerVersion: null,
+          },
+          b: {
+            currentVersion: '1.0.0',
+            dependentProjects: [],
+            newVersion: '1.2.0',
+            dockerVersion: null,
+          },
+        }
+      );
+
+      expect(tags).toEqual(['a-1.1.0', 'b-1.2.0']);
+    });
+
+    it('should produce no tag when both dockerVersion and newVersion are null with preferDockerVersion true', () => {
+      const { releaseGroup, releaseGroupToFilteredProjects } =
+        setUpReleaseGroup();
+      releaseGroup.releaseTag.preferDockerVersion = true;
+
+      const tags = createGitTagValues(
+        [releaseGroup],
+        releaseGroupToFilteredProjects,
+        {
+          a: {
+            currentVersion: '1.0.0',
+            dependentProjects: [],
+            newVersion: null,
+            dockerVersion: null,
+          },
+          b: {
+            currentVersion: '1.0.0',
+            dependentProjects: [],
+            newVersion: null,
+            dockerVersion: null,
+          },
+        }
+      );
+
+      expect(tags).toEqual([]);
+    });
+
+    it('should fall back to dockerVersion when preferDockerVersion is false but newVersion is null', () => {
+      const { releaseGroup, releaseGroupToFilteredProjects } =
+        setUpReleaseGroup();
+      releaseGroup.releaseTag.preferDockerVersion = false;
+
+      const tags = createGitTagValues(
+        [releaseGroup],
+        releaseGroupToFilteredProjects,
+        {
+          a: {
+            currentVersion: '1.0.0',
+            dependentProjects: [],
+            newVersion: null,
+            dockerVersion: '2024.01.abc123',
+          },
+          b: {
+            currentVersion: '1.0.0',
+            dependentProjects: [],
+            newVersion: null,
+            dockerVersion: '2024.01.abc123',
+          },
+        }
+      );
+
+      expect(tags).toEqual(['my-group-2024.01.abc123']);
+    });
+
+    it('should handle mixed independent group where some projects have docker version and some do not', () => {
+      const projects = ['a', 'b'];
+      const releaseGroup: ReleaseGroupWithName = {
+        name: 'my-group',
+        projects,
+        projectsRelationship: 'independent',
+        releaseTag: {
+          pattern: '{projectName}-{version}',
+          checkAllBranchesWhen: undefined,
+          requireSemver: true,
+          preferDockerVersion: true,
+          strictPreid: false,
+        },
+        changelog: undefined,
+        version: undefined,
+        versionPlans: false,
+        resolvedVersionPlans: false,
+      };
+      const releaseGroupToFilteredProjects = new Map().set(
+        releaseGroup,
+        new Set(projects)
+      );
+
+      const tags = createGitTagValues(
+        [releaseGroup],
+        releaseGroupToFilteredProjects,
+        {
+          a: {
+            currentVersion: '1.0.0',
+            dependentProjects: [],
+            newVersion: '1.1.0',
+            dockerVersion: '2024.01.abc123',
+          },
+          b: {
+            currentVersion: '1.0.0',
+            dependentProjects: [],
+            newVersion: '1.2.0',
+            dockerVersion: null,
+          },
+        }
+      );
+
+      // Project 'a' has dockerVersion so uses it; project 'b' falls back to newVersion
+      expect(tags).toEqual(['a-2024.01.abc123', 'b-1.2.0']);
+    });
+
     function setUpReleaseGroup() {
       const projects = ['a', 'b'];
       const releaseGroup: ReleaseGroupWithName = {

packages/nx/src/command-line/release/utils/shared.ts

@@ -313,16 +313,21 @@ export function createGitTagValues(
               );
             }
           } else {
-            // Use either docker version or semver version based on preference
-            tags.push(
-              interpolate(releaseGroup.releaseTag.pattern, {
-                version: preferDockerVersion
-                  ? projectVersionData.dockerVersion
-                  : projectVersionData.newVersion,
-                projectName: sanitizeProjectNameForGitTag(project),
-                releaseGroupName: releaseGroup.name,
-              })
-            );
+            // Use either docker version or semver version based on preference, with null fallback
+            const version = preferDockerVersion
+              ? (projectVersionData.dockerVersion ??
+                projectVersionData.newVersion)
+              : (projectVersionData.newVersion ??
+                projectVersionData.dockerVersion);
+            if (version) {
+              tags.push(
+                interpolate(releaseGroup.releaseTag.pattern, {
+                  version,
+                  projectName: sanitizeProjectNameForGitTag(project),
+                  releaseGroupName: releaseGroup.name,
+                })
+              );
+            }
           }
         }
       }
@@ -356,15 +361,18 @@ export function createGitTagValues(
           );
         }
       } else {
-        // Use either docker version or semver version based on preference
-        tags.push(
-          interpolate(releaseGroup.releaseTag.pattern, {
-            version: preferDockerVersion
-              ? projectVersionData.dockerVersion
-              : projectVersionData.newVersion,
-            releaseGroupName: releaseGroup.name,
-          })
-        );
+        // Use either docker version or semver version based on preference, with null fallback
+        const version = preferDockerVersion
+          ? (projectVersionData.dockerVersion ?? projectVersionData.newVersion)
+          : (projectVersionData.newVersion ?? projectVersionData.dockerVersion);
+        if (version) {
+          tags.push(
+            interpolate(releaseGroup.releaseTag.pattern, {
+              version,
+              releaseGroupName: releaseGroup.name,
+            })
+          );
+        }
       }
     }
   }