build: always use three-component version numbers

Someone thought we didn't use semantic versioning because we said "6.4" instead
of "6.4.0".  Don't trim .0.

CHANGES.rst

@@ -28,7 +28,6 @@ Unreleased
 .. _pull 1381: https://github.com/nedbat/coveragepy/pull/1381
 
 
-
 .. _changes_64:
 
 Version 6.4 — 2022-05-22

coverage/version.py

@@ -11,9 +11,7 @@
 def _make_version(major, minor, micro, releaselevel, serial):
     """Create a readable version string from version_info tuple components."""
     assert releaselevel in ['alpha', 'beta', 'candidate', 'final']
-    version = "%d.%d" % (major, minor)
-    if micro:
-        version += ".%d" % (micro,)
+    version = "%d.%d.%d" % (major, minor, micro)
     if releaselevel != 'final':
         short = {'alpha': 'a', 'beta': 'b', 'candidate': 'rc'}[releaselevel]
         version += f"{short}{serial}"

igor.py

@@ -385,12 +385,9 @@ def do_cheats():
     import coverage
     ver = coverage.__version__
     vi = coverage.version_info
-    anchor = f"{vi[0]}{vi[1]}"
-    if vi[2]:
-        anchor += f"{vi[2]}"
+    anchor = f"{vi[0]}-{vi[1]}-{vi[2]}"
     if vi[3] != "final":
-        anchor += vi[3][0]
-        anchor += f"{vi[4]}"
+        anchor += f"{vi[3][0]}{vi[4]}"
     branch = subprocess.getoutput("git rev-parse --abbrev-ref @")
     print(f"Coverage version is {ver}")
 

tests/test_version.py

@@ -21,9 +21,10 @@ def test_version_info(self):
         assert coverage.version_info[3] in ['alpha', 'beta', 'candidate', 'final']
 
     def test_make_version(self):
-        assert _make_version(4, 0, 0, 'alpha', 0) == "4.0a0"
-        assert _make_version(4, 0, 0, 'alpha', 1) == "4.0a1"
-        assert _make_version(4, 0, 0, 'final', 0) == "4.0"
+        assert _make_version(4, 0, 0, 'alpha', 0) == "4.0.0a0"
+        assert _make_version(4, 0, 0, 'alpha', 1) == "4.0.0a1"
+        assert _make_version(4, 0, 0, 'final', 0) == "4.0.0"
+        assert _make_version(4, 1, 0, 'final', 0) == "4.1.0"
         assert _make_version(4, 1, 2, 'beta', 3) == "4.1.2b3"
         assert _make_version(4, 1, 2, 'final', 0) == "4.1.2"
         assert _make_version(5, 10, 2, 'candidate', 7) == "5.10.2rc7"