diff --git a/ext/wasm/GNUmakefile b/ext/wasm/GNUmakefile
index 3d952c2615..1c74531403 100644
--- a/ext/wasm/GNUmakefile
+++ b/ext/wasm/GNUmakefile
@@ -226,17 +226,17 @@ DISTCLEAN_FILES += $(bin.stripccomments)
bin.c-pp := ./c-pp
$(bin.c-pp): c-pp.c $(sqlite3.c) $(MAKEFILE)
$(CC) -O0 -o $@ c-pp.c $(sqlite3.c) '-DCMPP_DEFAULT_DELIM="//#"' -I$(dir.top)
-define C-PP.JS
+define C-PP.FILTER
# Create $2 from $1 using $(bin.c-pp)
-# $1 = Input file: c-pp -f X.js
-# $2 = Output file: c-pp -o X.js
+# $1 = Input file: c-pp -f $(1).js
+# $2 = Output file: c-pp -o $(2).js
# $3 = optional c-pp -D... flags
$(2): $(1) $$(MAKEFILE) $$(bin.c-pp)
$$(bin.c-pp) -f $(1) -o $$@ $(3)
CLEAN_FILES += $(2)
endef
c-pp.D.vanilla ?=
-c-pp.D.esm ?= -Dsqlite3-es6-module-build
+c-pp.D.esm ?= -Dtarget=es6-module
# /end CPP-of-JS bits
########################################################################
@@ -301,8 +301,8 @@ $(sqlite3-api-build-version.js): $(bin.version-info) $(MAKEFILE)
pre-js.js.in := $(dir.api)/pre-js.js
pre-js.js.esm := $(dir.tmp)/pre-js.esm.js
pre-js.js.vanilla := $(dir.tmp)/pre-js.vanilla.js
-$(eval $(call C-PP.JS,$(pre-js.js.in),$(pre-js.js.vanilla),$(c-pp.D.vanilla)))
-$(eval $(call C-PP.JS,$(pre-js.js.in),$(pre-js.js.esm),$(c-pp.D.esm)))
+$(eval $(call C-PP.FILTER,$(pre-js.js.in),$(pre-js.js.vanilla),$(c-pp.D.vanilla)))
+$(eval $(call C-PP.FILTER,$(pre-js.js.in),$(pre-js.js.esm),$(c-pp.D.esm)))
post-js.js.in := $(dir.tmp)/post-js.js
post-js.js.vanilla := $(dir.tmp)/post-js.vanilla.js
post-js.js.esm := $(dir.tmp)/post-js.esm.js
@@ -317,14 +317,14 @@ $(post-js.js.in): $(post-jses.js) $(MAKEFILE)
cat $$i; \
echo "/* END FILE: $$i */"; \
done > $@
-$(eval $(call C-PP.JS,$(post-js.js.in),$(post-js.js.vanilla),$(c-pp.D.vanilla)))
-$(eval $(call C-PP.JS,$(post-js.js.in),$(post-js.js.esm),$(c-pp.D.esm)))
+$(eval $(call C-PP.FILTER,$(post-js.js.in),$(post-js.js.vanilla),$(c-pp.D.vanilla)))
+$(eval $(call C-PP.FILTER,$(post-js.js.in),$(post-js.js.esm),$(c-pp.D.esm)))
extern-post-js.js.in := $(dir.api)/extern-post-js.js
extern-post-js.js.vanilla := $(dir.tmp)/extern-post-js.vanilla.js
extern-post-js.js.esm := $(dir.tmp)/extern-post-js.esm.js
-$(eval $(call C-PP.JS,$(extern-post-js.js.in),$(extern-post-js.js.vanilla),$(c-pp.D.vanilla)))
-$(eval $(call C-PP.JS,$(extern-post-js.js.in),$(extern-post-js.js.esm),$(c-pp.D.esm)))
+$(eval $(call C-PP.FILTER,$(extern-post-js.js.in),$(extern-post-js.js.vanilla),$(c-pp.D.vanilla)))
+$(eval $(call C-PP.FILTER,$(extern-post-js.js.in),$(extern-post-js.js.esm),$(c-pp.D.esm)))
extern-pre-js.js := $(dir.api)/extern-pre-js.js
# Emscripten flags for --[extern-][pre|post]-js=...
@@ -644,13 +644,22 @@ CLEAN_FILES += $(speedtest1.js) $(speedtest1.wasm)
########################################################################
########################################################################
-# tester1 code:
-# tester1.js: for main thread and worker thread
-# tester1-esm.js: to be loaded from an ES6 Worker Module thread
-$(eval $(call C-PP.JS,tester1.c-pp.js,tester1.js))
-$(eval $(call C-PP.JS,tester1.c-pp.js,tester1-esm.js,-Dtester1-esm-worker))
-tester1.js: $(sqlite3.js)
-tester1-esm.js: $(sqlite3.mjs)
+# tester1 is the main unit and regression test application and needs to
+# be able to run in 4 separate modes to cover the primary use cases:
+#
+# 1) Load sqlite3 in the main UI thread of a conventional script.
+# 2) Load sqlite3 in a conventional Worker thread.
+# 3) Load sqlite3 as an ES6 module (ESM) in the main thread.
+# 4) Load sqlite3 as an ESM worker. (Not all browsers support this.)
+#
+# To that end, we require two separate builds of tester1.js:
+#
+# tester1.js: cases 1 and 2
+# tester1-esm.js: cases 3 and 4
+#
+# To create those, we filter tester1.c-pp.js with $(bin.c-pp)...
+$(eval $(call C-PP.FILTER,tester1.c-pp.js,tester1.js))
+$(eval $(call C-PP.FILTER,tester1.c-pp.js,tester1-esm.js,$(c-pp.D.esm)))
tester1: tester1.js tester1-esm.js
all: tester1
diff --git a/ext/wasm/api/extern-post-js.js b/ext/wasm/api/extern-post-js.js
index 3dc61ae050..acf7068fef 100644
--- a/ext/wasm/api/extern-post-js.js
+++ b/ext/wasm/api/extern-post-js.js
@@ -8,7 +8,7 @@
most of the associated JS code, runs outside of the
Emscripten-generated module init scope, in the current
global scope. */
-//#if sqlite3-es6-module-build
+//#if target=es6-module
const toExportForES6 =
//#endif
(function(){
@@ -110,10 +110,8 @@ const toExportForES6 =
exports["sqlite3InitModule"] = sqlite3InitModule;
/* AMD modules get injected in a way we cannot override,
so we can't handle those here. */
-//#if sqlite3-es6-module-build
- return self.sqlite3InitModule;
-//#endif
+ return self.sqlite3InitModule /* required for ESM */;
})();
-//#if sqlite3-es6-module-build
+//#if target=es6-module
export default toExportForES6;
//#endif
diff --git a/ext/wasm/api/pre-js.js b/ext/wasm/api/pre-js.js
index 41d13d6853..2e2fe66bc9 100644
--- a/ext/wasm/api/pre-js.js
+++ b/ext/wasm/api/pre-js.js
@@ -29,7 +29,7 @@ sqlite3InitModuleState.debugModule('self.location =',self.location);
4) If none of the above apply, (prefix+path) is returned.
*/
Module['locateFile'] = function(path, prefix) {
-//#if sqlite3-es6-module-build
+//#if target=es6-module
return new URL(path, import.meta.url).href;
//#else
'use strict';
diff --git a/ext/wasm/api/sqlite3-api-opfs.js b/ext/wasm/api/sqlite3-api-opfs.js
index 31fe45eda0..a3f73cc7b2 100644
--- a/ext/wasm/api/sqlite3-api-opfs.js
+++ b/ext/wasm/api/sqlite3-api-opfs.js
@@ -167,7 +167,7 @@ const installOpfsVfs = function callee(options){
return promiseReject_(err);
};
const W =
-//#if sqlite3-es6-module-build
+//#if target=es6-module
new Worker(new URL(options.proxyUri, import.meta.url));
//#else
new Worker(options.proxyUri);
diff --git a/ext/wasm/tester1-esm.html b/ext/wasm/tester1-esm.html
index 118ab676bd..498a1ab6a7 100644
--- a/ext/wasm/tester1-esm.html
+++ b/ext/wasm/tester1-esm.html
@@ -20,11 +20,6 @@
-
-
+