Update: Major version changelogs include all prereleases (#37)

* Update: Major version changelogs include all prereleases

For a new stable release following a prerelease sequence, the changelog
will include the commits for all of the prereleases going back to the
last stable release. For example, given the following release sequence:

- 6.7.8
- 6.8.0
- 7.0.0-alpha.0
- 7.0.0-alpha.1
- 7.0.0

The `7.0.0` changelog will include all changes since 6.8.0, whereas the
`7.0.0-alpha.1` changelog will include only changes since
`7.0.0-alpha.0`.

If we prefer to include all changes going back to the previous stable
release even for prerelease changelogs, that's an easy change and
actually simplifies the logic a bit.

* Update comment about version tags

lib/release-ops.js

@@ -250,18 +250,46 @@ function calculateReleaseFromGitLogs(currentVersion, logs, prereleaseId) {
 }
 
 /**
- * Gets all changes since the last tag that represents a version.
+ * Gets the range of commits to include in a changelog.
+ * If this will be the first stable release following a prerelease sequence,
+ * all commits going back to the previous stable release are included.
+ * @param {string[]} tags All prior version tags.
+ * @param {string} [prereleaseId] The prerelease identifier if this is a prerelease.
+ * @returns {string} The commit range to include in the changelog.
+ * @private
+ */
+function getChangelogCommitRange(tags, prereleaseId) {
+    let lastTag = null;
+
+    // If this will be a stable release after a prerelease...
+    if (!prereleaseId && semver.prerelease(tags[tags.length - 1])) {
+        let i = 2;
+
+        do {
+            lastTag = tags[tags.length - i];
+            i++;
+        } while (semver.prerelease(lastTag));
+    } else {
+        lastTag = tags[tags.length - 1];
+    }
+
+    return lastTag ? `${lastTag}..HEAD` : "";
+}
+
+/**
+ * Gets all changes for this release.
+ * If this will be the first stable release following a prerelease sequence,
+ * all changes from all prereleases since the last stable release are included.
  * @param {string} [prereleaseId] The prerelease identifier if this is a prerelease.
  * @returns {Object} An object containing all the changes since the last version.
  * @private
  */
 function calculateReleaseInfo(prereleaseId) {
 
-    // get most recent tag
+    // get last version tag
     const pkg = getPackageInfo(),
         tags = getVersionTags(),
-        lastTag = tags[tags.length - 1],
-        commitRange = lastTag ? `${lastTag}..HEAD` : "";
+        commitRange = getChangelogCommitRange(tags, prereleaseId);
 
     // get log statements
     const logs = ShellOps.execSilent(`git log --no-merges --pretty=format:"* %H %s (%an)%n%b" ${commitRange}`).split(/\n/g);
@@ -427,6 +455,7 @@ module.exports = {
     generateRelease,
     publishRelease,
     calculateReleaseInfo,
+    getChangelogCommitRange,
     calculateReleaseFromGitLogs,
     writeChangelog
 };

tests/lib/release-ops.js

@@ -46,6 +46,38 @@ describe("ReleaseOps", () => {
 
     });
 
+    describe("getChangelogCommitRange", () => {
+
+        it("returns an empty string when there are no prior releases", () => {
+            const tags = [];
+            const range = ReleaseOps.getChangelogCommitRange(tags);
+
+            assert.strictEqual(range, "");
+        });
+
+        it("finds the most recent tag for normal releases", () => {
+            const tags = ["1.0.0", "1.0.1"];
+            const range = ReleaseOps.getChangelogCommitRange(tags);
+
+            assert.strictEqual(range, "1.0.1..HEAD");
+        });
+
+        it("finds the most recent tag for prereleases", () => {
+            const tags = ["1.0.0", "1.0.1", "2.0.0-alpha.0", "2.0.0-alpha.1"];
+            const range = ReleaseOps.getChangelogCommitRange(tags, "beta");
+
+            assert.strictEqual(range, "2.0.0-alpha.1..HEAD");
+        });
+
+        it("finds the last stable tag for a new stable following prereleases", () => {
+            const tags = ["1.0.0", "1.0.1", "2.0.0-alpha.0", "2.0.0-rc.0"];
+            const range = ReleaseOps.getChangelogCommitRange(tags);
+
+            assert.strictEqual(range, "1.0.1..HEAD");
+        });
+
+    });
+
     describe("calculateReleaseFromGitLogs()", () => {
 
         it("should create a patch release when only bug fixes are present", () => {
@@ -252,6 +284,36 @@ describe("ReleaseOps", () => {
             });
         });
 
+        it("should create the next stable release following a prerelease", () => {
+            const logs = [
+                    "* 7e8a43b2b6350e13a61858f33b4099c964cdd758 Breaking: Remove API (githubhandle)",
+                    "* 0c07d6ac037076557e34d569cd0290e529b3318a Docs: Something else (Committer Name)",
+                    "* 196d32dbfb7cb37b886e7c4ba0adff499c6b26ac Fix: Something else (Abc D. Efg)"
+                ],
+                releaseInfo = ReleaseOps.calculateReleaseFromGitLogs("2.0.0-rc.0", logs);
+
+            assert.deepStrictEqual(releaseInfo, {
+                version: "2.0.0",
+                type: "major",
+                changelog: {
+                    fix: [
+                        "* [`196d32d`](https://github.com/eslint/eslint-release/commit/196d32dbfb7cb37b886e7c4ba0adff499c6b26ac) Fix: Something else (Abc D. Efg)"
+                    ],
+                    docs: [
+                        "* [`0c07d6a`](https://github.com/eslint/eslint-release/commit/0c07d6ac037076557e34d569cd0290e529b3318a) Docs: Something else (Committer Name)"
+                    ],
+                    breaking: [
+                        "* [`7e8a43b`](https://github.com/eslint/eslint-release/commit/7e8a43b2b6350e13a61858f33b4099c964cdd758) Breaking: Remove API (githubhandle)"
+                    ]
+                },
+                rawChangelog: [
+                    "* [`7e8a43b`](https://github.com/eslint/eslint-release/commit/7e8a43b2b6350e13a61858f33b4099c964cdd758) Breaking: Remove API (githubhandle)",
+                    "* [`0c07d6a`](https://github.com/eslint/eslint-release/commit/0c07d6ac037076557e34d569cd0290e529b3318a) Docs: Something else (Committer Name)",
+                    "* [`196d32d`](https://github.com/eslint/eslint-release/commit/196d32dbfb7cb37b886e7c4ba0adff499c6b26ac) Fix: Something else (Abc D. Efg)"
+                ].join("\n")
+            });
+        });
+
         it("should gracefully handle unformatted commit messages", () => {
             const logs = [
                     "* 70222e95932d3a391ac5717252e13b478d686ba9 0.4.0-alpha.4 (Nicholas C. Zakas)",