Fixes #542 Add previous tag option (#550)

src/Action.ts

@@ -197,7 +197,7 @@ export class Action {
             return body
         }
 
-        const response = await this.releases.generateReleaseNotes(this.inputs.tag)
+        const response = await this.releases.generateReleaseNotes(this.inputs.tag, this.inputs.generateReleaseNotesPreviousTag)
         const releaseNotes = response.data.body
 
         if (!body || body.trim() === "") {

src/Inputs.ts

@@ -15,6 +15,7 @@ export interface Inputs {
     readonly createdReleaseName?: string
     readonly discussionCategory?: string
     readonly generateReleaseNotes: boolean
+    readonly generateReleaseNotesPreviousTag?: string
     readonly immutableCreate: boolean
     readonly makeLatest?: "legacy" | "true" | "false" | undefined
     readonly omitBodyDuringUpdate: boolean
@@ -138,6 +139,11 @@ export class CoreInputs implements Inputs {
         return generate == "true"
     }
 
+    get generateReleaseNotesPreviousTag(): string | undefined {
+        const previousTag = core.getInput("generateReleaseNotesPreviousTag")
+        return previousTag || undefined
+    }
+
     get immutableCreate(): boolean {
         const immutable = core.getInput("immutableCreate")
         return immutable == "true"

src/Releases.ts

@@ -36,7 +36,7 @@ export interface Releases {
 
     getByTag(tag: string): Promise<ReleaseByTagResponse>
 
-    generateReleaseNotes(tag: string): Promise<GenerateReleaseNotesResponse>
+    generateReleaseNotes(tag: string, previousTag?: string): Promise<GenerateReleaseNotesResponse>
 
     listArtifactsForRelease(releaseId: number): Promise<ListReleaseAssetsResponseData>
 
@@ -106,12 +106,18 @@ export class GithubReleases implements Releases {
         })
     }
 
-    async generateReleaseNotes(tag: string): Promise<GenerateReleaseNotesResponse> {
-        return this.git.rest.repos.generateReleaseNotes({
+    async generateReleaseNotes(tag: string, previousTag?: string): Promise<GenerateReleaseNotesResponse> {
+        const params: any = {
             owner: this.inputs.owner,
             repo: this.inputs.repo,
             tag_name: tag,
-        })
+        }
+        
+        if (previousTag) {
+            params.previous_tag_name = previousTag
+        }
+        
+        return this.git.rest.repos.generateReleaseNotes(params)
     }
 
     async getByTag(tag: string): Promise<ReleaseByTagResponse> {