From 434fa94bdca63be629304bfde231ffa25d6754ed Mon Sep 17 00:00:00 2001
From: Sheetal Nandi <shkamat@microsoft.com>
Date: Fri, 15 Mar 2019 15:52:15 -0700
Subject: [PATCH] Passing --force option to build, builds project from start

---
 src/compiler/tsbuild.ts                    |  1 +
 src/testRunner/unittests/tsbuild/sample.ts | 18 ++++++++++++++++--
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/compiler/tsbuild.ts b/src/compiler/tsbuild.ts
index c649665cf7..e9311bd9a4 100644
--- a/src/compiler/tsbuild.ts
+++ b/src/compiler/tsbuild.ts
@@ -1178,6 +1178,7 @@ namespace ts {
         }
 
         function getOldProgram(proj: ResolvedConfigFileName, parsed: ParsedCommandLine) {
+            if (options.force) return undefined;
             const value = builderPrograms.getValue(proj);
             if (value) return value;
             return readBuilderProgram(parsed.options, readFileWithCache) as any as T;
diff --git a/src/testRunner/unittests/tsbuild/sample.ts b/src/testRunner/unittests/tsbuild/sample.ts
index c225840a56..a813f28ee8 100644
--- a/src/testRunner/unittests/tsbuild/sample.ts
+++ b/src/testRunner/unittests/tsbuild/sample.ts
@@ -168,14 +168,14 @@ namespace ts {
         });
 
         describe("can detect when and what to rebuild", () => {
-            function initializeWithBuild() {
+            function initializeWithBuild(opts?: BuildOptions) {
                 const fs = projFs.shadow();
                 const host = new fakes.SolutionBuilderHost(fs);
                 const builder = createSolutionBuilder(host, ["/src/tests"], { verbose: true });
                 builder.buildAllProjects();
                 host.clearDiagnostics();
                 tick();
-                builder.resetBuildContext();
+                builder.resetBuildContext(opts ? { ...opts, verbose: true } : undefined);
                 return { fs, host, builder };
             }
 
@@ -254,6 +254,20 @@ namespace ts {
                     [Diagnostics.Building_project_0, "/src/tests/tsconfig.json"],
                 );
             });
+
+            it("rebuilds from start if --f is passed", () => {
+                const { host, builder } = initializeWithBuild({ force: true });
+                builder.buildAllProjects();
+                host.assertDiagnosticMessages(
+                    getExpectedDiagnosticForProjectsInBuild("src/core/tsconfig.json", "src/logic/tsconfig.json", "src/tests/tsconfig.json"),
+                    [Diagnostics.Project_0_is_up_to_date_because_newest_input_1_is_older_than_oldest_output_2, "src/core/tsconfig.json", "src/core/anotherModule.ts", "src/core/anotherModule.js"],
+                    [Diagnostics.Building_project_0, "/src/core/tsconfig.json"],
+                    [Diagnostics.Project_0_is_up_to_date_with_d_ts_files_from_its_dependencies, "src/logic/tsconfig.json"],
+                    [Diagnostics.Building_project_0, "/src/logic/tsconfig.json"],
+                    [Diagnostics.Project_0_is_up_to_date_with_d_ts_files_from_its_dependencies, "src/tests/tsconfig.json"],
+                    [Diagnostics.Building_project_0, "/src/tests/tsconfig.json"]
+                );
+            });
         });
 
         describe("downstream-blocked compilations", () => {