Use a lockfile to persist Pub's installed version constellation.

utils/tests/pub/version_solver_test.dart

Index: utils/tests/pub/version_solver_test.dart
diff --git a/utils/tests/pub/version_solver_test.dart b/utils/tests/pub/version_solver_test.dart
index f5d5d4f6d45588386e5842dc6e0e4546526a2549..6f56fce5f334c0dfe29f6f4c6ccf7c8ef8b1aeda 100644
--- a/utils/tests/pub/version_solver_test.dart
+++ b/utils/tests/pub/version_solver_test.dart
@@ -7,6 +7,7 @@
 #import('dart:io');
 #import('dart:isolate');
 
+#import('../../pub/lock_file.dart');
 #import('../../pub/package.dart');
 #import('../../pub/pubspec.dart');
 #import('../../pub/source.dart');
@@ -128,6 +129,61 @@ main() {
     'bar': '1.1.0'
   });
 
+  testResolve('with compatible locked dependency', {
+    'myapp 0.0.0': {
+      'foo': 'any'
+    },
+    'foo 1.0.0': { 'bar': '1.0.0' },
+    'foo 1.0.1': { 'bar': '1.0.1' },
+    'foo 1.0.2': { 'bar': '1.0.2' },
+    'bar 1.0.0': {},
+    'bar 1.0.1': {},
+    'bar 1.0.2': {}
+  }, lockfile: {
+    'foo': '1.0.1'
+  }, result: {
+    'myapp': '0.0.0',
+    'foo': '1.0.1',
+    'bar': '1.0.1'
+  });
+
+  testResolve('with incompatible locked dependency', {
+    'myapp 0.0.0': {
+      'foo': '>1.0.1'
+    },
+    'foo 1.0.0': { 'bar': '1.0.0' },
+    'foo 1.0.1': { 'bar': '1.0.1' },
+    'foo 1.0.2': { 'bar': '1.0.2' },
+    'bar 1.0.0': {},
+    'bar 1.0.1': {},
+    'bar 1.0.2': {}
+  }, lockfile: {
+    'foo': '1.0.1'
+  }, result: {
+    'myapp': '0.0.0',
+    'foo': '1.0.2',

[Jennifer Messerly, 2012/07/19 18:45:34]

so if the lockfile is incompatible, it just gets upgraded?

[nweiz, 2012/07/19 18:56:54]

Yes. This should only happen when the user modifies the pubspec, which
presumably means they want updated versions of their files.

[Jennifer Messerly, 2012/07/19 19:06:30]

Makes sense

+    'bar': '1.0.2'
+  });
+
+  testResolve('with unrelated locked dependency', {
+    'myapp 0.0.0': {
+      'foo': 'any'
+    },
+    'foo 1.0.0': { 'bar': '1.0.0' },
+    'foo 1.0.1': { 'bar': '1.0.1' },
+    'foo 1.0.2': { 'bar': '1.0.2' },
+    'bar 1.0.0': {},
+    'bar 1.0.1': {},
+    'bar 1.0.2': {},
+    'baz 1.0.0': {}
+  }, lockfile: {
+    'baz': '1.0.0'
+  }, result: {
+    'myapp': '0.0.0',
+    'foo': '1.0.2',
+    'bar': '1.0.2'
+  });
+
   testResolve('dependency back onto root package', {
     'myapp 1.0.0': {
       'foo': '1.0.0'
@@ -226,7 +282,7 @@ main() {
 //   can keep track of server traffic.
 }
 
-testResolve(description, packages, [result, error]) {
+testResolve(description, packages, [lockfile, result, error]) {
   test(description, () {
     var sources = new SourceRegistry();
     source1 = new MockSource('mock1');
@@ -266,8 +322,16 @@ testResolve(description, packages, [result, error]) {
       });
     }
 
+    var realLockFile = new LockFile.empty();
+    if (lockfile != null) {
+      lockfile.forEach((name, version) {
+        version = new Version.parse(version);
+        realLockFile.packages[name] = new PackageId(source1, version, name);
+      });
+    }
+
     // Resolve the versions.
-    var future = resolveVersions(sources, root);
+    var future = resolveVersions(sources, root, realLockFile);
 
     if (result != null) {
       expect(future, completion(predicate((actualResult) {